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Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 190465: Nonstandard dice can produce interesting distributions of outcomes. You have two balanced,
six-sided dice. One is a standard dice, with faces having 1,2,3,4,5 and 6 spots. The other die
has three faces with 0 spots and three faces with 6 spots. Find the probability distribution
for the total number of spots Y on the up-faces when you roll these two dice.
Click here to see answer by edjones(3299)   |
Question 190466: A study of iron deficiency among infants compared samples of infants following different
feeding regimens. One group contained breast-fed infants, while the children in other group
were fed a standard baby formula without any iron supplements. Here are summary results
on blood hemoglobin levels at 12 months of age.
Group n Mean s
Breast-fed 23 13.3 1.7
Formula 19 12.4 1.8
a. Is there significant evidence that the mean hemoglobin level is higher among breastfed
babies? State null hypothesis and alternate hypothesis and conduct a t-test.
b. Give a 95% confidence interval for the mean difference in hemoglobin level between
the two populations of infants.
Click here to see answer by stanbon(26297)  |
Question 190142: I'm working on some multiple choice problems and I'm a little stumped on them. Here's what I've come up with, if someone could tell me if I've got them or if not what is right so I know.
1.A 2.B 3.D 4.B 5.B 6.D 7.D 8.D 9.C 10.A
11.A 12.B 13.D 14.A 15.C 16.D 17.D 18.D 19.C 20.A
Here's the problems
1.In a one-tailed test
A.The rejection region is in one of the tails.
B.The rejection region is split between the tails.
C.The p-value is always less than the significance level.
D.The p-value is always more than the significance level.
2.To conduct a one sample test of means and use the z distribution as the test statistic
A.We need to know the population standard deviation.
B.We can use the sample standard deviation provided n is at least 30.
C.We need n to be at least 5.
D.Both a and b are correct.
3.Which of the following statements are correct when deciding whether to use the z or the t distribution
A.Use z when the sample size is 30 or more.
B.Use z when we have a normal population and know the standard deviation.
C.Use t when the population is normal, the population standard deviation is not known, and n is less than 30.
D.All of the above statements are correct.
4.Which of the following is not a requirement for the two-sample test of means for independent samples when both samples contain less than 30 observations?
A.Normal populations
B.Equal population standard deviations
C.Equal sample sizes
D.All of the above are required.
5.To conduct a test of means for two independent samples which of the following are always required?
A.At least one of the samples must have 30 observations
B.Both samples must have 30 observations
C.n and n (1 - ) must be 5.
D.None of the above.
6.The term MSE
A.Is called the mean square error.
B.Is found by SSE/(n - k).
C.Is an estimate of the common population variance.
D.All of the above.
7.Which of the following is not an assumption required for ANOVA?
A.The populations are normally distributed
B.The populations have equal standard deviations
C.The samples are independent.
D.None of the above.
8.Under which of the following conditions will the computed value of F be negative?
A.When there is no difference in the treatment means
B.When there is no difference in the block means
C.When the SS total is larger than SST.
D.F cannot be negative.
9.Suppose we conduct an ANOVA test of four treatment means and reject the null hypothesis. Construction of a confidence interval for the difference between the first and second sample mean revealed the interval to be 10 plus
or minus 12. We conclude
A.This pair of means differ.
B.This pair of means does not differ.
C.Because we do not know the units involved, we cannot draw any conclusion.
D.Because we do not know the degrees of freedom, we cannot draw any conclusion.
10.In a two-way ANOVA the second source of variation is due to
A.Random error.
B.Blocks.
C.Total variation
D.None of the above
11.In a contingency table a sample of 400 people is classified by gender and hair color (4 groups: blond, brown, black, and red). How many degrees of freedom are there?
A.3
B.8
C.399
D.None of the above.
12.For a 2 goodness-of-fit test
A.There is only one degree of freedom.
B.The rejection region is in the upper right tail.
C.The scale of measurement is interval.
D.We must assume a normal population.
13.To find the expected frequency in a contingency table
A.Take the square root of the degrees of freedom.
B.Multiple the row and column totals and divide by the grand total.
C.Use the total number of observations minus one.
D.None of these.
14.Suppose we are conducting a Chi-Square Goodness of Fit test of hypothesis to determine if a set of observations with 6 categories meets an expected set. How many degrees of freedom are there?
A.5
B.97
C.3
D.None of these.
15.Under what conditions could the 2 distribution assume negative values?
A.When the sample size is small.
B.When the cell frequencies are all equal.
C.When the degrees of freedom is 1.
D.Never
16.A scatter diagram is a chart
A.In which the dependent variable is scaled along the vertical axis.
B.In which the independent variable is scaled along the horizontal axis.
C.That portrays the relationship between two variables.
D.All of the above.
17.In correlation analysis
A.We consider several independent variables.
B.We study the strength of the association between two variables.
C.We consider the intercept with the Y-axis.
D.None of the above.
18.The sample coefficient of correlation
A.Has the same sign as the slope, i.e. b.
B.Can range from -1.00 up to 1.00
C.Is also called Pearson's r.
D.All of the above.
19.The coefficient of determination
A.Is the square of the coefficient of correlation.
B.Cannot be negative.
C.Reports the percent of the variation in the dependent variable explained by the independent variable.
D.All of the above.
20.Suppose we developed the following least squares regression equation: Y' = 3.5 +2.1 . Which of the following statement is correct?
A.The dependent variable increases 2.1 for an increase of 1 in .
B.The equation crosses the Y-axis at 3.5.
C.If = 5, then Y' = 14.
D.All of the above.
Click here to see answer by stanbon(26297) |
Question 189500: An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was $275.66 with a standard deviation of $78.11.
(a) At the 5 percent level of significance, does this sample prove a violation of the guideline that the average patient should pay no more than $250 out-of-pocket?
State your hypotheses and decision rule.
(b) Is this a close decision?
Click here to see answer by stanbon(26297) |
Question 190740: Question 1
You want to prove that a population mean is not 7. Data is ratio and a large sample size will be used (n = 225). When the sample is done the sample mean is computed to be 7.2 and the sample standard deviation is 1.5. Test the hypothesis using an alpha of 5%. Use formal hypothesis testing and compute the p-value.
Question 2
An associate asks for your help in deciphering the following Anova table, indicating that a test of means was performed on the average age of people at three different locations. Unfortunately the person leaves before you can get any further explanation or detail, but you know the results must be presented before senior staff within twenty minutes!
Use the formal 5-step hypothesis testing model to describe the test, the results and interpret the results in conversational English.
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 700.0 2 350.0 4.00 0.0288 3.32
Within Groups 2625.0 30 87.5
Total 3325.0 32
Click here to see answer by stanbon(26297) |
Question 190794: There are 8 physics textbooks, 7 us history textbooks, 4 calculus textbooks, and 3 resource books on a shelf. Assuming the books in each category are DISTINCT how many ways can they be arranged if books of the same kind must be together?
Click here to see answer by solver91311(5072)  |
Question 190805: At Nick and Francine's wedding reception, the wedding party were asked to dance during one song. Each person on the dance floor had to dance with every other person. If there were 18 people on the dance floor, how many "Dancing partners" were there?
Click here to see answer by solver91311(5072) |
Question 190798: There are 8 physics textbooks, 7 us history textbooks, 4 calculus textbooks, and 3 resource books on a shelf. Assuming the books in each category are DISTINCT how many ways can they be arranged if books of the same kind must be together?
Click here to see answer by stanbon(26297) |
Question 190814: The probability that a trainee will remain with a company is 0.6. The probability that an employee earns more than Rs.10, 000 per year is 0.5. The probability that an employee is a trainee who remained with the company or who earns more than Rs.10, 000 per year is 0.7. What is the probability that an employee earns more than Rs.10, 000 per year given that he is a trainee who stayed with the company.
Click here to see answer by stanbon(26297) |
Question 190959: NEED HELP ASAP ON THIS!!! PLEASE PLEASE?? THANK YOU SO MUCH!!
A U.S. dime is supposed to weigh 2.268 grams. A random sample of 15 circulated dimes showed a mean weight of 2.256 grams with a standard deviation of .026 grams. Using α = .05, is the mean weight of all circulated dimes lower than the specification? Explain your decision.
Hypothesis Test: Mean vs. Hypothesized Value
2.26800 hypothesized value
2.25600 mean Sample data
0.02600 std. dev.
0.00671 std. error
15 n
14 df
-1.79 t
.0478 p-value (one-tailed, lower)
2.24160 confidence interval 95.% lower
2.27040 confidence interval 95.% upper
0.01440 half-width
Click here to see answer by stanbon(26297) |
Question 190974: CAN you HELP ASAP
thank you sooooooooo very much
Now suppose that Jacob is a basketball player who averages scoring 1.65 points whenever he has a one-and-one free throw situation. Let's use that information to calculate what his free-throw shooting percentage is. Let's use the symbols p and E to represent what we're talking about:
p = success probability whenever Jacob shoots a free throw
E = expected value for number of points scored in a one-and-one situation
In Takeisha's case, we knew that p = 0.74, and we used that information to solve for E. In Jacob's case we know that E = 1.65, and we want to solve for p. To do this, use exactly the same procedure that you did with Takeisha, except instead of working with the number 0.74, simply use the symbol p. This should lead you to an equation involving p and E. Since you know the value of E in Jacob's case, plug in that value and solve for p. (It's a quadratic equation, so you'll need to use the quadratic formula.)
Jacob's success probability when shooting free throws
Click here to see answer by stanbon(26297) |
Question 190981: A random sample of 100 students at southern
university was collected. The mean age was found to be 24.2 years, with a standard deviation of 3.4 years
A) what percent of students are over 27.6 years old
b)what percent of the students are between 20.8 and 24.2 years old
c) If a student is selected at random from southern univesity, what is the probability that he or she will be over 20.8 years old
I could use some help
Click here to see answer by stanbon(26297) |
Question 191043: I started most of the work but I am not sure if I am doing it right. Please help.
Hypothesis Testing for Mean (Small Samples)
3. Metro Bank claims that the mean wait time for a teller during peak hours is less than 4 minutes. A random sample of 20 wait times has a mean of 2.6 minutes with a sample standard deviation of 2.1 minutes.
a. Use the critical value z0 method from the normal distribution to test for the population mean . Test the company’s claim at the level of significance = 0.05.
xbar = 2.6
µ = 4
s = 2.1
n = 20
d.f = n – 1 = 20 – 1 = 19
To find the critical value, use table 5 in Appendix B with d.f. = 19 and 0.05 in the “One Tail, ” column. Because the test is a left-tailed test, the critical value is negative. So
t0 = -1.729
1. H0 : u >= 4 minutes
Ha : u < 4 minutes
2. level of significance = 0.05
3. Test statistics: t = xbar - µ / s/√n (2.6-4)/[2.1/sqrt(20)] = -2.9814
4. P-value or critical z0 or t0.
5. Rejection Region: t < -1.729
6. Decision: Since -2.9814 is in the reject interval, Reject Ho.
7. Interpretation: The mean time is not <= 4 minutes
b. Use the critical value z0 method from the normal distribution to test for the population mean. Test the company’s claim at the level of significance = 0.01.
xbar = 2.6
µ = 4
s = 2.1
n = 20
d.f = n – 1 = 20 – 1 = 19
To find the critical value, use table 5 in Appendix B with d.f. = 19 and 0.01 in the “One Tail, level of significance ” column. Because the test is a left-tailed test, the critical value is negative. So
t0 = 2.539
1. H0 : u >= 4 minutes
2. Ha : u < 4 minutes
3. level of significance = 0.01
4. Test statistics:
5. P-value or critical z0 or t0.
6. Rejection Region:
7. Decision:
8. Interpretation:
Hypothesis Testing for Proportions.
4. In a recent poll, it was found that 43% of registered U.S. voters would vote for the incumbent president. If 100 registered voters were sampled randomly, it was found that 35% would vote of the incumbent. Test the claim that the actual proportion is 43%.
1. H0 :
Ha :
2. level of significance =
3. Test statistics:
4. P-value or critical z0 or t0.
5. Rejection Region:
6. Decision:
7. Interpretation:
Click here to see answer by stanbon(26297) |
Question 191017: Not sure on how to complete the following. I think I did the first one right.
Introduction to Hypothesis Testing
State the claim mathematically. Then write the null and alternative hypothesis. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed.
a. In a recent poll, it was found that 43% of registered U.S. voters would vote for the incumbent president. If 100 registered voters were sampled randomly, it was found that 35% would vote of the incumbent. Test the claim that the actual proportion is 43%.
Answer: claim: The claim “that 43% of registered U.S voters would vote for the incumbent president”
H0: p = 43
Ha: p not equal to 43
Test: Because Ha contains the not eual to 43, the testis a two-tailed hypothesis test.
b. Convicted murderers receive a sentence of an average of 18.7 years in prison. A criminologist wants to perform a hypothesis test to determine whether the mean sentence by one particular judge differs from 18.7 years.
Answer: claim: the mean sentence by one particular judge differs from 18.7 years
H0:
Ha:
Test:
Click here to see answer by stanbon(26297) |
Question 191029: Did I do this right?
Hypothesis Testing for the Mean (Large Samples)
Convicted murderers receive a sentence of an average of 18.7 years in prison. A criminologist wants to perform a hypothesis test to determine whether the mean sentence by one particular judge differs from 18.7 years. A random sample of 40 cases from the court files from this judge is taken. It is found that sample mean is 17.2 years. Assume that the population standard deviation is 7.4 years. Test at the 0.05 significance level.
Solution: Criminologist wants to perform a hypothesis test to determine whether the mean sentence by one particular judge differs from 18.7 years
1. H0: µ = 18.7
Ha: µ ≠18.7
2. significance level = 0.05
3. Test statistics: The test is two-tailed
z = xbar - µ / ơ/√n = (17.2-18.7)/[7.4/sqrt(40)] = -1.2820
4. P-value or critical z0 or t0. The critical values are – z0 = -1.96 and z0 = 1.96
5. Rejection Region: z < -1.96 and z > 1.96
6. Decision: since test statistic is not in the reject interval, Fail to reject Ho.
7. Interpretation: The test does not provide strong evidence for rejecting the belief the average sentence is 18.7
b. Use the P-value method.
1. H0: µ = 18.7
Ha: µ ≠18.7
2. significance level = 0.05
3. Test statistics: z = xbar - µ / ơ/√n = (17.2-18.7)/[7.4/sqrt(40)] = -1.2820
4. P-value or critical z0 or t0. In Table 4, the area corresponding to z = -1.2820 is 0.1003. Because the test is a two-tailed test, the P-value is equal to twice the area to the left of z = 0.2820
P = 2(0.1003) = 0.2006
5. Rejection Region: ?
6. Decision: Since p-value is greater than 0.05 fail to reject Ho.
7. Interpretation: The test does not provide strong evidence for rejecting the belief the average sentence is 18.7
Click here to see answer by stanbon(26297) |
Question 191001: b) The odds against student X solving a Business statistics problem are 8 to 6, and odds in favour of student Y solving the problem are 14 to 16.
1. What is the chance that the problem will be solved if they both try independent of each other?
2. What is the probability that none of them is able to solve the problem?
Question 2: Marks: 1+3+2+3+1= 10
For the frequency distribution given below:
Length of Service No of employees
7.5-7.9 6
8.0-8.4 22
8.5-8.9 36
9.0-9.4 18
9.5-9.9 14
10.0-10.4 4
Calculate
(i) Mean
(ii) Standard deviation
(iii) Co-efficient of Variation
(iv) Mean Deviation (from median)
(v) Range
Question 3: Marks: 2+2=4
a) How many distinct four-digit numbers can be performed from the following integers 1, 2, 3,4,5,6 if each integer is used only once?
b) What would be the shape and name of the frequency distribution if
1. mean=median=mode
2. mean>median>mode
Question 4: Marks: 2+6=8
a) Describe the situation in which two variables are perfect positively correlated?
b) The cost of output at a factory is thought to depend on the number of units produced. Data have been collected for the number of units produced each month in the last six months, and the associated costs, as follows;
Output
(‘000s of units) X Cost
($’000) Y
2 9
3 11
1 7
4 13
3 11
5 15
Calculate the correlation coefficient and comment on your result.
Click here to see answer by stanbon(26297) |
Question 191344: There are 10 houses in your neighborhood having a yard sale. You want to go to at least 5 of the houses having a yard sale. How many different combinations of yard sales can you attend?
My answer choices are:
A) 386
B) 638
C) 848
D) 1,286
E) 9,858,240
Click here to see answer by solver91311(5072) |
Question 191368: What is the probability of rolling a die three times, and getting outcomes of 1, 2, and 3, in this order.
I tried to work as hard as I can on this problem but I can't find a way to know the probability that will be in THE SAME ORDER as the question asks.
I did (1/6) x (1/6) x (1/6) and that got me 1/216
I don't know... Should I do (1/6)^3 x (1/6)^3 x (1/6)^3?
I hope this doesn't count as one of my daily problem limit because I really tried my hardest.
Thanks
Click here to see answer by solver91311(5072) |
Question 191397: There are 12 teams competing in a cheerleading competition. The order in which the teams perform is randomly selected. There are 4 teams from your city competing. What is the probability (rounded to three decimal places) that the first three teams to perform are from your city?
Answer Choices:
A) 0.008
B) 0.010
C) 0.018
D) 0.250
E) 0.333
I think the answer is (4/12) x (3/11) x (2/10) x (1/9) which = 0.002
I don't think that's right so please help.
Thanks
Click here to see answer by stanbon(26297) |
Question 191245: Can you please help me solve this problem?
A sample of 200 policemen showed that 65% thought the courts were too lenient, while a sample of 200 lawyers showed that only 45% thought the judges were too lenient. Test the claim that policemen, more often believe, that judges are too lenient on the accused. Use a 0.04 level of significance to test this claim.
Click here to see answer by stanbon(26297) |
Question 191385: Out of the 50 students on student council, 29 are either on the honor roll or write for the school paper. There are 38 student council members who are on the honor roll and 5 that write for the schol paper. What is the probability that a randomly selected student council member is both on the honor roll and writes for the school paper?
Answer Choices:
A) 2/25
B) 7/25
C) 21/50
D) 29/50
E) 33/50
I got 7/50 but it's not one of the answer choices. Clearly, 38+5=43 so the remaining is 7. 7/50 seems the people who are left. I need more clarification on it.
Thanks
Click here to see answer by jim_thompson5910(13794) |
Question 191424: Can you help me solve this?
In a survey of full-time college students, 400 out of 700 memers of a fraternity reported that they held a part-time job. Of 800 non-fraternity, 490 stated that they held a part-time job. Does the data support the belief that fewer fraternity members hold part-time jobs than non-fraternity members. Use a 0.05 level of significance.
Click here to see answer by stanbon(26297) |
Question 191420This question is from textbook
: 15.18 Sixty-four students in an introductory college economics class were asked how many credits they
had earned in college, and how certain they were about their choice of major. Research question:
At α = .01, is the degree of certainty independent of credits earned? Certainty
Credits Earned Very Uncertain Somewhat Certain Very Certain Row Total
0–9 12 8 3 23
10–59 8 4 10 22
60 or more 1 7 11 19
Col Total 21 19 24 64
This question is from textbook
Click here to see answer by stanbon(26297) |
Question 191547: In a shipment of 50 transformers, 10 are known to be defective. If 30 transformers are picked at random, what is the probability that all 30 are nondefective? Assume that all transformers look alike and have an equal probability of being chosen.
Click here to see answer by Edwin McCravy(2922) |
Question 191500: A coin-operated drink machine was designed to discharge a mean of 6 ounces of coffee per cup. In a test of the machine, the discharge amounts in 18 randomly chosen cups of coffee from the machine were recorded. The sample mean and sample standard deviation were 6.16 ounces and 0.28 ounces, respectively. If we assume that the discharge amounts are normally distributed, is there enough evidence, at the 0.1 level of significance, to conclude that the true mean discharge,m , differs from 6 ounces?
Perform a two-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.)
The value of the test statistic (round to the nearest three decimals):
The p-value (Round to at least three decimals):
At the 0.1 level of significance can we conclude that the true mean discharge differs from 6 ounces?
Click here to see answer by stanbon(26297) |
Question 191708: The mean salary offered to students who are graduating from Coastal State University this year is $24,260, with a standard deviation of $3643. A random sample of 85 Coastal State students graduating this year has been selected. What is the probability that the mean salary offer for these 85 students is $24,750 or more?
Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places.
Click here to see answer by stanbon(26297) |
Question 191806: Nonstandard dice can produce interesting distributions of outcomes. You have two balanced,
six-sided dice. One is a standard dice, with faces having 1,2,3,4,5 and 6 spots. The other die
has three faces with 0 spots and three faces with 6 spots. Find the probability distribution
for the total number of spots Y on the up-faces when you roll these two dice.
Click here to see answer by stanbon(26297) |
Question 191707: Consider the following random sample of diameter measurements (in inches) of 18 softballs:
4.88, 4.88, 4.76, 4.82, 4.69, 4.75, 4.72, 4.86, 4.81, 4.75, 4.86, 4.73, 4.78, 4.72, 4.73, 4.78, 4.71, 4.87.
If we assume that the diameter measurements are normally distributed, find a 95% confidence interval for the mean diameter of a softball. Then complete the table below.
Carry your intermediate computations to at least three decimal places. Round your answers to two decimal places.
What is the lower limit of the confidence interval?
What is the upper limit of the confidence interval?
Click here to see answer by stanbon(26297) |
Question 191844: I have a few questions that I am having a very difficult time with.
1.) A 28-year-old man pays $ 175 for a one-year life insurance policy with coverage of $140,000. If the probability that he will live through the year is 0.9993, what is the expected value for the insurance policy?
2.)Two dice are rolled. Find the odds that the score on the dice is either 10 or at most 5.
3.)What are the odds in favor of getting at most two heads in three successive flips of a coin?
4.)Assume that the weight loss for the first two months of a diet program has a uniform distrbiution over the interval 6 to 12 pounds. Find the probability that a person on this diet loses between 9 and 12 pounds in the first two months.
Click here to see answer by stanbon(26297) |
Question 191498: A coin-operated drink machine was designed to discharge a mean of 6 ounces of coffee per cup. In a test of the machine, the discharge amounts in 18 randomly chosen cups of coffee from the machine were recorded. The sample mean and sample standard deviation were 6.16 ounces and 0.28 ounces, respectively. If we assume that the discharge amounts are normally distributed, is there enough evidence, at the 0.1 level of significance, to conclude that the true mean discharge,m , differs from 6 ounces?
Perform a two-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.)
a) the null hypothsesis Ho:
b) the alternate hypothesis H1:
c)the type of statistic:
Click here to see answer by stanbon(26297) |
Question 191494: A consumer advocacy group is doing a large study on car rental practices. Among other things, the consumer group would like to do a statistical test regarding the mean monthly mileage,m , of cars rented in the U.S. this year. The consumer group has reason to believe that the mean monthly mileage of cars rented in the U.S. this year is different from last year's mean, which was 2850 miles.
The group plans to do a statistical test regarding the value of m. It chooses a random sample of monthly mileages and computes the mean of the sample to be 2675 miles and the standard deviation to be 800 miles.
Based on this information, answer the questions below.
What are the null hypothesis (H o) and the alternate hypothosis (H1)that should be used for the test?
Click here to see answer by stanbon(26297) |
Question 191461: Can you help me solve this problem?
Researchers with a health spa have developed five different diet-exercise programs to help obese people lose weight.Results are given below as to the amount of weight lost in each program. Is there evidence to suggest that there is a difference in weight loss based on the given regimen? Use a 0.05 level of significance to test the claim.
Weight Loss Program A: 13,16,16,7,12,7,4,12,9
Weight Loss Program B: 12,8,6,9,11,6,10,5,7,9,11,13,11,19,15
Click here to see answer by stanbon(26297) |
Question 191950: Namclear agency is a body tasked with the clearance of all bank guaranteed cheques from all commecial banks in the country. According to the agency it was observed that 1 in 20 cheques in Namibia are fraudulent. suppose you radomly selected 20 cheques from this population of cheques.
1 what is the probability that no cheque in the samle will be fraudulent?
2 what is the probability that one cheque will in the sample will fraudulent?
3 what is the probability that one or fewer cheques in the sample will be fraudulent?
4 what is the probability that at least 2 cheques in the sample will be fraudulent?
Click here to see answer by stanbon(26297) |
Question 192056: Can you please help me solve this problem?
A car dealer thinks it is easier to change spark plugs in Japanese cars than in American cars. They changed a number of spark plugs in each kind of car and the results are given, in minutes below:
Japabese: 15,21,22,13,18,21,20,21
American: 19,24,19,16,19,23
At the 0.05 level of significance, is there sufficient evidence to back his theory?
Click here to see answer by stanbon(26297) |
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Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905
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