Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 152632: The probability is 1 in 4,000,000 that a single auto trip in the United States will result in a fatality. Over a lifetime, an average U.S. driver takes 50,000 trips. (a) What is the probability of a fatal accident over a lifetime? Hint: Assume independent events. Why might the assumption of the independence be violated? (b) Why might a driver be tempted not to use a seat belt “just on this trip”?
Click here to see answer by Fombitz(2113)   |
Question 153019: 1. Suppose you use five different letters to make a computer password. Find the number of possible five letter passwords.
I got 11,881,376 using the formula 26 C 5. Is this correct?
2. How many different ways can someone arrange 8 books on a shelf? I got 64.
3. If the first three digits of someone's phone number (no area code) are 555, how many different phone numbers could they have? I got 11,881,373
I used 26 to the 5th power.
Thanks for your help.
Click here to see answer by jim_thompson5910(13787)  |
Question 152890: Hi Can you please help me with this problem.
a book inventory record contains the following information:
a) Title: more mysteries
b)Author: Roger Mortimer
c) date of publication 1998
d) list price $25.00
e) number in stock: 6
for the information (a) to (e) list the hightest level of measurement as raio, interval, ordinal, or nominal.
can you pleae help me.
thank JIll
Click here to see answer by mducky2(55) |
Question 152990: Test the hypothesis that the average age of the students in the following group is 35.
Student # Age
1............ 37
2............ 43
3............ 22
4............ 36
5............ 35
6............ 28
7............ 44
8............ 33
9............ 26
10........... 36
11........... 21
12............ 53
13............ 38
14............ 44
15............ 31
Develop a problem statement
What is the average age of the students in the following group?
Create the hypothesis, null and alternate based on the problem statement
Decide on one- or two-tailed test
Develop the decision criteria, significance level, and critical value (if the P-value is not used)
Calculate the test statistic
What is the decision of the null hypothesis?
Click here to see answer by stanbon(26259) |
Question 153081: Help Please,
in the book it says for problems 9-14, pplease provide the follwing information.
a) what is the level of significance? State the null and the alternate hypothesis. Will you use a left-tailed, right tailed, or two tailed tes?
b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. What is the value of the sample test statistics?
c) find(or estimate) the P-value. Sketch the sampling distribution and show the area corresponding to the P-value.
d)Based on your answers in parts A to C, will you reject or fail to reject the null hypothesis? are the data statistically significant at level A?
e) State your conclusion in the context of the application.
Now here is the problem for number 10
Gentle Ben is a Morgan horse at a Colorado dude ranch. Over the past 8 weeks, a veterinarian took the following glucose readings from this horse (in mg/100ml).
93 88 82 105 99 110 84 89
the sample mean is x with a bar over it = 93.8. let x be a random variable representing glucose readings taken from Gentle Ben. We may assume that x has a normal distribution, and we know from past experience that o=12.5. The mean glucose level for horses should be u= 85 mg/100 ml do these data indicate that Gentle Ben has an overall overage glucose level hight than 85? Use a=0.05
Please help me
jill
Click here to see answer by stanbon(26259) |
Question 153141: Someone please help me
The sale price of a car is $12,590 which is 20% of the original price. What is the original price?
also..
Jim is able to sale a statue for $670 he made a 35% profit. What is the original price?
Someone please help me ill be really appreciative
Click here to see answer by stanbon(26259) |
Question 153094: Can you please help me with this.
Recently the national average yield on municipal bonds has been u=4.19%. A random sample of 16 Arizona municipal bonds gave an average yield of 5.11% with a sample standard deviation s= 1.15%. does this indicate that the population mean yield for all Arizona municipal bonds is greater than the national average? Us a= 0.05. Assume x is normally distributed.
a) state the null and alternate hypothesis.
b) indentify the sampling distribution to be used. the standard normal distribution or the student's T distribution. find the critical value (s).
c) compute the z or t value of the sample test statistic.
d) find the P value or an interval containing the P value for the sample test statistic.
e) Based on your answers to A through D, decide whether or not to reject the null hypothesis at the ficen significance level. Explain your conclusion in the context of the problem.
thank you
carol
Click here to see answer by stanbon(26259) |
Question 153080: can some one please help me with this i do not even know how to get started with this.
consumer reports stated that the mean time for a chrysler concorde to go from 0 to 60 miles per hour was 8.7 seconds.
a) if you want to set up a statistical test to challenge the claim of 8.7 seconds what would you use for the null hypothesis? AM I CORRECT WHEN THIS ANSWER Ho: u = 8.7?
b) the town of leadville, colorado, has an elevation over 10,000 feet. Suppose you wanted to test the claim that the average time to accelerate from 0 to 60 miles per hour is longer in leadville ( because of less oxygen). What would you use for the alternate hypothesis? I HOPE THIS IS RIGHT TOO H1 : U> 10,000
C) Suppose you made an engine modification and you think that they average time to accelerate from 0 to 60 miles per hour has been reduced. What would you use for the alernate hypothesis? NOW THIS IS WHERE I GET CONFUSED. BUT I AM GOING TO TRY IT H1: U< 0 TO 60
d) For each of the tests in parts (b) and (c), would the P-value area be on the left, on the right, or on both sides of the mean> Explain your answer in each case?
This part i do not understand at all?
Julie
Click here to see answer by stanbon(26259) |
Question 152891: Can you please help me with this problem?
the cost of one serving of peanut butter (in cents) for a random sample of 19 jars of peanut butter was to be:
22 27 32 26 26 19 16
26 14 21 20 21 20 17
12 32 17 9 16
a) give the five-number summary ( low, Q1, median, Q3, high)
b) calculate the IQR..
Thank you for your help in advance
carol
Click here to see answer by stanbon(26259) |
Question 153288This question is from textbook
: 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?
This question is from textbook
Click here to see answer by stanbon(26259) |
Question 153265This question is from textbook
: Trevor wants to buy a local restaurant. 60% of the business days it's open, the restaurant makes a $850 profit. Estimate the probability that the store will make p$850 profit more than 17 out of the next 20 business days. If this actually happened, might you suspect that p is greater than 0.60?
High school seniors in SAT math had a mean score of 500 with a standard deviation 100. In an ACT, the mean was 18 and a standard deviation of 6. Both scores are normally distributed.
a) An engineering school only accepts SAT and ACT scores in the top 10%. What's the minimum SAT and ACT scores for this program
b) Suppose the school accepts SAT and ACT scores in the top 20%. What are the minimum SAT and ACT scores for this program?
c) IF the school accepts the top 60% scores, what are the minimum SAT and ACT scores?This question is from textbook
Click here to see answer by stanbon(26259) |
Question 153427: Can somone please tell me how to do this i am so confused.
Let X be a random variable that represents the length of time it takes a student to write a term paper for Dr. Adam's Sociology class. After interviewing many students, it was found that X has an approximately normal distribution with mean U = 6.8 hours and standard deviation O=2.1 hours.
Convert each of the following X intervals to standardized Z intervals:
a) x is less than or equal to 7.5
b) 5 is less than or equal to X is less than or equa to 8
c) x is greater than or equal to 4
Convert each of the following z intervals to raw score X intervals
d) z is greater than or equal to -2
e) 0 is less than or equal to Z is less than or equal to 2
f) Z is less than or equal to 3
Thank you for your help in advance
jill
Click here to see answer by stanbon(26259) |
Question 153425: Can you please help me with this?
Researchers at a pharmaceutical company have found that the effective time duration of a safe dosage of a pain relief drug is normally distributed with mean 2 hours and standard deviation 0.3 hour. For a patient selected at random:
a) what is the probability that the drug will be effective for 2 hours or less?
b) what is the probability that the drug will be effective for 1 hour or less?
c) what is the probability that the drug will be effective for 3 hours or more?
I greatly appreciate all your help.
Julie
Click here to see answer by stanbon(26259) |
Question 153494: In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found that 1,143 were positive. (a) Construct a 95 percent confidence interval for the population proportion of positive drug tests. (b) Why is the normality assumption not a problem, despite the very small value of p?
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Question 153491: A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were
3.087 3.131 3.241 3.241 3.270 3.353 3.400 3.411 3.437 3.477
a). Construct a 90 percent confidence interval for the true mean weight. (b) What sample size would be necessary to estimate the true weight with an error of ± 0.03 grams with 90 percent confidence? (c) Discuss the factors which might cause variation in the weight of Tootsie Rolls during manufacture.
Click here to see answer by Fombitz(2113) |
Question 153749: Can someone help me with this?
You roll two fair dice, one red and one green.
a) what is the probability of getting a number less than 5 on both?
b) what is the probability of getting a sum of 9 on the two dice?
c) what is the probability of getting a 5 on both?
thank you
JIll
Click here to see answer by Fombitz(2113) |
Question 153724: How many different student body officers are possible if there are four seniors, five juniors, and three sophomores running for the student body offices: senior class president, junior class president, and sophmore class president?
Click here to see answer by stanbon(26259) |
Question 154392: A certain airplane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a 1- hour flight is .02. What is the probability that (a) both will fail? (b) Neither will fail? (c) one or the other will fail? Show all steps carefully.
Click here to see answer by stanbon(26259) |
Question 154838: Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, the unpopped kernels were counted. There were 86. a) Construct a 90 percent confidence interval for the proportion of all kernels that would not pop. (b) Check the normality assumption. (c) Try the Very Quick Rule. Does it work well here? Why, or why not? (d) Why might this sample not be typical?
Click here to see answer by stanbon(26259) |
Question 154857This question is from textbook
: Last year, a study showed that the average ATM cash withdrawal took 65 seconds with a standard deviation of 10 seconds. The study is to be repeated this year. How large a sample would be needed to estimate this year's mean with 95 percent confidence and an error of ±4 seconds?This question is from textbook
Click here to see answer by Fombitz(2113) |
Question 155200: Consider the following frequency table of the performance ratings on a scale of 1–good, 2–fair, and 3–poor, bestowed on their local baseball team by a collection of 100 fans:
Rating -Frequency
1- 20
2- 30
3- 50
The cumulative relative frequencies for each performance rating are
a. 1–20%, 2–30%, 3–50%
b. 1–20%, 2–50%, 3–100%
c. 1–80%, 2–70%, 3–50%
d. 1–50%, 2–30%, 3–20%
Click here to see answer by stanbon(26259) |
Question 155199: Suppose a frequency table consists of six categories. If all six categories contain the same number of observations, the interior angles of each section of the associated pie chart would be
a. 30 degrees.
b. 45 degrees.
c. 60 degrees.
d. 90 degrees
Click here to see answer by stanbon(26259) |
Question 155279: what is the standard error of the mean
10,8,4,4,6,2,3,2,2,5,3,8,5,7,9,9,6,9,5,4,1,5,4,2,8
Click here to see answer by stanbon(26259) |
Question 155280: given the following raw scores on a standard 10 poing scale. calculate the 95% confidence interval (use the t-score method) the interval is from ___ to___10,8,4,4,6,2,3,2,2,5,3,8,5,7,9,9,6,9,5,4,1,5,4,2,8,
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Question 155313: You are involved in the evaluation of viewership of television shows for your local TV station.
You have been tasked to determine a 95% confidence interval for the viewing of a show called 'CSI Phoenix'.
You have randomly queried 400 local adults and determined that 150 of them watched the last episode of the show.
>> create a 95% confidence interval for the proportion of folks in the population that viewed the show
Click here to see answer by stanbon(26259) |
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