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Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 188411: Art, Becky, Carl, Denise are lined up to buy tickets.
A. How many different permutations are possible?
B. Suppose Ed was also in line. How many permutations would there be?
C. In how many of the permutations of the five is Becky first?
D. What is the probability that a permutation of this five is chosen at random will have Becky first?
Click here to see answer by stanbon(26259)   |
Question 188357: CAN SOMEONE PLEASE HELP ME IN STATISTICS? THANK YOU SO MUCH!!!
There are three hospitals in a municipal area. The following data show the number of outpatient surgeries performed at each hospital last week. At the .05 significance level, can we conclude there is a difference in the mean number of surgeries performed by hospital or by day of the week? Why or why not?
Number of Surgeries Performed
St. Luke's
Monday 14
Tuesday 20
Wednesday 16
Thursday 18
Friday 20
St. vincents
18
24
22
20
28
Mercy
24
18
20
22
24
Randomized blocks ANOVA
Mean n Std. Dev
20.53333333 17.600 5 2.608 Treatment 1
20.53333333 22.400 5 3.847 Treatment 2
20.53333333 21.600 5 2.608 Treatment 3
18.667 3 5.033 Block 1
20.667 3 3.055 Block 2
19.333 3 3.055 Block 3
20.000 3 2.000 Block 4
24.000 3 4.000 Block 5
20.533 15 3.583 Total
ANOVA table
Source SS df MS F p-value
Treatments 66.13 2 33.067 4.28 .0546
Blocks 51.73 4 12.933 1.67 .2482
Error 61.87 8 7.733
Total 179.73 14
Click here to see answer by stanbon(26259) |
Question 188613: Use the following pairs of bivariate data to find the equation of the regression line. Assume a linear correlation exists.
x 3 4 5 5 6 7
y 9 8 5 4 4 4
The equation of the regression line is:
Choose between the following
A. y = 12.67 – 1.40x
B. y = 1.40 + 12.67x
C. y = 1.40 – 12.67 x
D. y 12.67 + 1.40x
Click here to see answer by solver91311(5072)  |
Question 188607: Money made for a sample of movies in America and foreign markets is below. The amounts are in millions of dollars.
Domestic 214 80 181 134 124 150 108 304
Foreign 253 78 177 180 198 78 120 350
Find r, the linear correlation coefficient
Choose between
A. .63
B. .94
C. .88
D. .74
Click here to see answer by stanbon(26259) |
Question 188631This question is from textbook a survey of mathematics with applications
: 24) Seven employees at a large company were asked the number of addtional years they planned to work before retirement. their response was 10,23,28,4,1,6,12
A) detrimine the standard deviation.
26) the amount of money that 7 people spent on perscription medication in a year are as follows: $600,$100,$850,$350,$250,$140,$300.
A)detrmine the range
B)determine the standard deviationThis question is from textbook a survey of mathematics with applications
Click here to see answer by Edwin McCravy(2920) |
Question 188714: Attached is a probability question with two parts. I feel I have question A figured out. However question B I cannot figure out and cannot figure out a solution. Could someone please help me with these two questions and include a formula with steps. Thanks in advance. The question is:
A drug used to reduce high blood pressure produces side effects in 4% of the patients. Three patients who have taken the drug are selected at random. What is the probability that:
A. they all had side effects.
B. none of them had side effects
The answer I came up with for A is: .000064
Any help is greatly appreciated. Thanks again.
Click here to see answer by stanbon(26259) |
Question 188609: Four different brands of cola are tested in a taste test(everybody is supposed to be blindfolded). The following table shows how many people were able to identify 4 popular brands of cola. At a .05 level of significance, test the claim that the results are equally distributed.
Brand Observed
Coca Cola 66
Pepsi Cola 86
Diet Cola 18
Diet Pepsi 30
Find the critical value. Choose between
A. 14.860
9. 488
C. 7.815
D. 12.838
And Find the test Statistic
A. 0.88
B. 8.49
C. 11.20
D. 59.52
Click here to see answer by stanbon(26259) |
Question 188610: I am just really having a problem with this...
A store manager believes that 25% of their customers come in on Monday, 15% on
Tuesday, 15% on Wednesday, 15% on Thursday, and 30% on Friday. Test at the .01
level if the manager is correct if one week the following number of customers
came in to the store.
Monday: 32 Customers
Tuesday: 15 customers
Wednesday: 17 customers
Thursday: 16 customrs
Friday" 40 customers
Find the critical value. Choose between
A. 13.277
B. 9.236
C. 7.779
D. 15.868
Find the test statistic. Choose between
A. 1.36
B. 0.13
C. 1.63
D. –0.13
Click here to see answer by stanbon(26259) |
Question 188739: A research organization tested microwave ovens. At alpha=.10, is there asignificant difference in the average price of the three types of ovens? The data and an ANOVA table are shown below. Based on the ANOVA table is the null hypothesis of equal price rejected or not rejected? On what did you base your decision? Be sure to justify your answer.
Microwave oven watts 1000 900 800
Price in dollars $270.00 $240.00 $180.00
$245.00 $135.00 $155.00
$190.00 $160.00 $200.00
$215.00 $230.00 $120.00
$250.00 $250.00 $140.00
$230.00 $200.00 $180.00
$200.00 $140.00
$210.00 $130.00
Anova: Single Factor
SUMMARY
Groups Count Sum Average Variance
1000 6 1400 233.3333 796.6667
900 8 1625 203.125 1549.554
800 8 1245 155.625 795.9821
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 21729.73 2 10864.87 10.11821 0.001019 3.52189
Within Groups 20402.08 19 1073.794
Total 42131.82 21
Click here to see answer by stanbon(26259) |
Question 188755: 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(26259) |
Question 188355: CAN SOMEONE PLEASE HELP ME IN STATISTICS? THANK YOU SO MUCH!!!!
In a bumper test, three types of autos were deliberately crashed into a barrier at 5 mph, and the resulting damage (in dollars) was estimated. Five test vehicles of each type were crashed, with the results shown below. Research questions: (a) Are the mean crash damages the same or significantly different among these three vehicles? (b) Are there any significant differences between pairs of groups? What test did you use? Explain.
Crash Damage in Dollars
Goliath
1100
750
970
1000
850
Varmint
1290
1400
1390
1850
1100
Weasel
1100
1500
1000
1250
1920
Click here to see answer by stanbon(26259) |
Question 188762: One group of accounting students took a distance learning class, while another group took the same course in a traditional classroom. At α = .10, is there a significant difference in the mean scores listed below? (a) State the hypotheses. (b) State the decision rule and sketch it. (c) Find the test statistic. (d) Make a decision. (e) Use Excel to find the p-value and interpret it.
Click here to see answer by stanbon(26259) |
Question 188853: I'm dying a slow death in statistics. Please help!
In 2004, a small dealership leased 21 Chevrolet Impalas on 2-year leases. When the cars were returned in 2006, the mileage was recorded (see below). Is the dealer's mean significantly greater than the national average of 30,000 miles for 2-year leased vehicles, using the 10 percent level of significance?
Mileage:
40,060 24,960 14,310 17,370 44,740 44,550 20,250
33,380 24,270 41,740 58,630 35,830 25,750 28,910
25,090 43,380 23,940 43,510 53,680 31,810 36,780
Click here to see answer by stanbon(26259) |
Question 188808: I am having some trouble with this one question on my homework,would some one please help me,
The data below are the gestation periods, in months, of randomly selected animals and their corresponding life spans, in years.
Gestation, x 8 2.1 1.3 1 11.5 5.3 3.8 24.3
Life span, y 30 12 6 3 25 12 10 40
a. Find the equation of the regression line for the given data. Round the line values to the nearest two decimal places.
b. Using the equation found in part a, predict the life span when the gestation is 10 months. Round to the nearest absence.
I would like to thank you in advance for helping me by using your own time . Thank you very much.
Click here to see answer by stanbon(26259) |
Question 188882: Suppose the Real Estate Board of Greater Vancouver conducts a study of the number of first-time applicants who are successful in passing the certification examination for real estate salespeople on their first attempt. Two samples were taken from the list of applicants: those who were already employed by a real estate agency and those who were recent university graduates who had not taken a full-time job. Results are shown in the table below:
Real Estate Employees Unemployed Graduates
Sample Size 100 200
Number passing 47 102
a.What is the sample proportion of real estate employees who passed the exam on their first attempt?
b.What is the sample proportion of unemployed college graduates who passed the exam on their first attempt?
c.If the null hypothesis is H0: R – U = 0, what is the value of the test statistic? R = proportion of real estate employees passing the exam on their first attempt, U = proportion of unemployed graduates passing the exam on their first attempt.
d. State your conclusion on the result of the test for H0: R – U = 0 if the alternate hypothesis is: H0: R – U < 0. Use = 0.05.
Click here to see answer by stanbon(26259) |
Question 188881: SafeRoad Stores is redesigning the checkout lanes in its stores throughout the country. Two designs have been suggested. Tests on customer checkout times have been conducted at two stores where the two new systems have been installed. A summary of the sample data follows:
System A
Sample size = 25
Sample mean checking out time = 4.3 minutes
Sample standard deviation = 2.0 minutes
System B
Sample size = 25
Sample mean checkout time = 3.3 minutes
Sample standard deviation = 3.0 minutes
At the 0.05 significance level, perform a statistical test to see the two systems are significantly different.
Click here to see answer by stanbon(26259) |
Question 188924: I am having some trouble with my Statistics homework, could some one please help me I have completed the chart but I am stuck on the rest.I am not sure if the the r is right. I am very gratful for your help.
x
8
2.1
1.3
1
11.5
5.3
3.8
24.3
Ex= 57.3
y
30
12
6
3
25
12
10
40
Ey=138
xy
240
25.2
7.8
3
287.5
63.6
38
972
Exy= 1,637.1
x2
64
4.41
1.69
1
132.25
28.09
14.44
590.49
Ex(2)= 836.37
y2
900
144
36
9
625
144
100
1600
Ey(2)= 3558
Use the last row of the table to show the column totals.
n = 8
Use the last row of the table to show the column totals.
n = 8
r = 0.915931
Using the r calculated in problem the significance of the correlation coefficient using = 0.01 and the claim p ≠ 0.
Answer:
1. H0 : p = 0
Ha : p ≠0
2. = 0.01
3. Find t
4. t0 =
5. Rejection region:
6. Decision:
7. Interpretation:
I would like to thank you in advance for all your help.
Click here to see answer by stanbon(26259) |
Question 188975: High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this
hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld
sound meter. Noise level is defined as “Low” (under 88 decibels), “Medium” (88 to 91 decibels),or “High” (92 decibels or more). There are three flight phases (Climb, Cruise, Descent). Research
question: At α = .05, is the cockpit noise level independent of flight phase? (Data are from
Capt. Robert E. Hartl, retired.) Noise
Noise Level Climb Cruise Descent Row Total
Low 6 2 6 14
Medium 18 3 8 29
High 1 3 14 18
Col Total 25 8 28 61
Click here to see answer by stanbon(26259) |
Question 188974: 11.26 The results shown below are mean productivity measurements
(average number of assemblies completed per hour) for a random sample of workers at each of three plants. Research question: Are the mean hourly productivity levels the same for workers in these three plants? Productivity
Hourly Productivity of Assemblers in Plants
Plant Finished Units Produced Per Hour
A (9 workers) 3.6 5.1 2.8 4.6 4.7 4.1 3.4 2.9 4.5
B (6 workers) 2.7 3.1 5.0 1.9 2.2 3.2
C (10 workers) 6.8 2.5 5.4 6.7 4.6 3.9 5.4 4.9 7.1 8.4
Click here to see answer by stanbon(26259) |
Question 188973: Ages for the 2005 Boston Red Sox pitchers are shown below. (a) Assuming this is a random sample
of major league pitchers, at the 5 percent level of significance does this sample show that the
true mean age of all American League pitchers is over 30 years? State your hypotheses and decision
rule and show all work. (b) If there is a difference, is it important? (c) Find the p-value and
interpret it.
Ages of Boston Red Sox Pitchers, October 2005
Arroyo 28 Foulke 33 Mantei 32 Timlin 39
Clement 31 Gonzalez 30 Miller 29 Wakefield 39
Embree 35 Halama 33 Myers 36 Wells 42
Click here to see answer by stanbon(26259) |
Question 189051: In a region 4% of the population is thought to have a certain disease. A standard diagnostic test will correctly identify 92% of the people who have the disease. However, the test also incorrectly diagnoses 10% of those who do not have the disease as having the disease. A randomly selected person in the region is tested for the disease.
What is the probability the test comes back positive?
What is the probability the test comes back positive and the person actually has the disease?
If the test comes back positive, what then is the conditional probability that he actually does have the disease?
Click here to see answer by stanbon(26259) |
Question 188806: CAN SOMEONE PLEAE HELP ME SOLVE THIS? THANK YOU SO MUCH!!
There are three hospitals in a municipal area. The following data show the number of outpatient surgeries performed at each hospital last week. At the .05 significance level, can we conclude there is a difference in the mean number of surgeries performed by hospital or by day of the week? Why or why not?
NUMBER OF SURGERIES PERFORMED
ST. LUKES ST. VINCENTS MERCY
MONDAY 14 18 24
TUESDAY 20 24 18
WEDNESDAY 16 22 20
THURSDAY 18 20 22
FRIDAY 20 28 24
RANDOMIZED BLOCKS ANOVA
Mean n Std. Dev
17.600 5 2.608 Treatment 1
22.400 5 3.847 Treatment 2
21.600 5 2.608 Treatment 3
18.667 3 5.033 Block 1
20.667 3 3.055 Block 2
19.333 3 3.055 Block 3
20.000 3 2.000 Block 4
24.000 3 4.000 Block 5
20.533 15 3.583 Total
ANOVA table
Source SS df MS F p-value
Treatments 66.13 2 33.067 4.28 .0546
Blocks 51.73 4 12.933 1.67 .2482
Error 61.87 8 7.733
Total 179.73 14
Click here to see answer by stanbon(26259) |
Question 189062: I have a question for my statsitics homework, would someone please help me one last time. Thank you.
I did the chartand found the r, but I am still having trouble with the rest.
x
4
5
5
6
4
7
3
8
4
Ex= 46
y
62
69
76
83
74
91
59
94
73
Ey= 681
xy
248
345
380
498
296
637
177
752
292
Exy=3625
x2
16
25
25
36
16
49
9
64
16
Ex2=256
y2
3844
4761
5776
6889
5476
8281
3481
8836
5329
Ey2=52,673
r= -.0870
here is my question:
Using the r calculated, test the significance of the correlation coefficient using alpha = 0.01 and the claim k = 0. Design the test using the 7-steps hypothesis test.
Answer:
1. H0 : k = 0
Ha : k
2. alpha = 0.01
3. Find the test statistic t.
4. Find the critical t0
5. Define the rejection region.
6. State the statistical decision.
7. Application interpretation.
Once again I would like to thank you for helping me and using your own time . Thank you in advance.
Click here to see answer by stanbon(26259) |
Question 189114: Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard deviation of 4.45 pages.
(a) At the .01 level of significance, is the true mean greater than 10?
(b) Use Excel to find the right-tail p-value.
Click here to see answer by stanbon(26259) |
Question 189125: ``A coin was flipped 60 times and came up heads 38 times.
(a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations.
(b) Calculate a p-value and interpret it.
Click here to see answer by stanbon(26259) |
Question 189177: Radio station WQXP has 15% of the market in Houston and 40% of the market in Dallas. Of the total number of radio listeners in Houston and Dallas, 85% live in Houston and 15% in Dallas.
If you know that the listener is indeed listening to station WQXP, what then is the probability that the listener lives in Dallas?
Click here to see answer by stanbon(26259) |
Question 189250: A standard test for diabetes is based on glucose levels in the blood after fasting for a prescribed period. For untreated diabetics the mean fasting glucose is found to be 11.74mmol/L, and the standard deviation is 3.50mmol/L. The level of glucose appears to be approximately normally distributed.
To operate a simple diagnostic test based on fasting glucose levels, we need to set a cut off point, C, so that if the patients fasting glucose level is at least C we say they have diabetes. If it is lower we say they do not have diabetes.
(i) For the moment, suppose we use C=6.5. What is the probability that a diabetic is incorrectly diagnosed as not having diabetes?
NOTE: I have attempted this question, but got stuck, because I'm not sure if what I'm doing is correct. I found that the P(6.5 < x < 11.74) = 0.4325, but don't know where to go from here...
Click here to see answer by stanbon(26259) |
Question 189206: 60% of the patients at a clinic are children. 10% of the children and 1/4 of the adults use alternative medicine. A patient is selected at random. 1) what is the probability the slected patient uses alternative medicine? 2) what is the probability that the selected patient is a child that uses alternative medicine?
Click here to see answer by stanbon(26259) |
Question 189265: Kinesha and Donna are playing a tennis match where the winner must win 2 sets in order to win the match. Kinesha starts strong but tires quickly. The probability that Kinesha wins the first set is 0.6. But the probability she wins the second set is only 0.5. And if a third set is needed, the probability that Kinesha wins the third set is only 0.3. Put all this information into a tree diagram to answer the following questions.
What is the probability that Kinesha wins the match?
What is the conditional probability that Kinesha wins the match if Donna wins the first set?
What is the conditional probability that Donna wins the match if Kinesha wins the first set?
What is the probability that 3 sets are played? .5
Click here to see answer by Mathtut(3670) |
Question 189484: Four salesmen play "odd man out" to see who pays for lunch. They each flip a coin, and if there is a salesman whose coin doesn't match the others he pays for lunch. (For instance, he might get heads while the other three get tails.) What is the probability that there is an "odd man" the first time they flip?
Click here to see answer by Edwin McCravy(2920) |
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