A sample of 45 customers who drive luxury cars showed that their average distance driven between oil changes was 3187 miles with a sample standard deviation of 42.40 miles. Another sample of 40 customers who drive compact lower-price cars resulted in an average distance of 3214 miles with a standard deviation of 50.70 miles. Suppose that the standard deviations for the two populations are not equal. (a) Construct a 95% confidence interval for the difference in the mean distance between oil changes for all luxury cars and all compact lower-price cars. (b) Using the 1% significance level, can you conclude that the mean distance between oil changes is lower for all luxury cars than for all compact lower-price cars?

A sample of 45 customers who drive luxury cars showed that their average distance driven between oil changes was 3187 miles with a sample standard deviation of 42.40 miles. Another sample of 40 customers who drive compact lower-price cars resulted in an average distance of 3214 miles with a standard deviation of 50.70 miles. Suppose that the standard deviations for the two populations are not equal. (a) Construct a 95% confidence interval for the difference in the mean distance between oil changes for all luxury cars and all compact lower-price cars. (b) Using the 1% significance level, can you conclude that the mean distance between oil changes is lower for all luxury cars than for all compact lower-price cars?

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

A researcher collected sample data for 17 women ages 18 to 24. The sample had a mean serum cholesterol level (measured in mg/100 mL) of 188.4, with a standard deviation of 9.2. Assuming that serum cholesterol levels for women ages 18 to 24 are normally distributed, find a 90% confidence interval for the mean serum cholesterol level of all women in this age group. Then find the lower limit and upper limit of the 90% confidence interval. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
A survey conducted by the AAA showed that a family of four spends on average $215.60 per day while on vacation. Suppose a sample of 64 families of four vacationing at Niagara Falls resulted in a sample mean of $252.45 per day with a sample standard deviation of $74.50. Develop a 98% confidence interval for the mean amount that a family of four visiting Niagara Falls will spend.
A student at a four-year college claims that mean enrollment at four-year colleges is higher than at two-year colleges in the United States. Two surveys are conducted. Of the 35 four-year colleges surveyed, the mean enrollment was 5,466 with a standard deviation of 8,191. Of the 35 two-year colleges surveyed, the mean enrollment was 5,068 with a standard deviation of 4,777. Test the student's claim at the 0.10 significance level.a) The null and alternative hypothesis would be: H0:μF=μTH1:μF<μT H0:pF=pTH1:pF>pT H0:pF=pTH1:pF≠pT H0:pF=pTH1:pF<pT H0:μF=μTH1:μF>μT H0:μF=μTH1:μF≠μT b) Determine the test statistic. Round to two decimals.t=c) Find the p-value and round to 4 decimals.p =
A student at a four-year college claims that mean enrollment at four-year colleges is higher than at two-year colleges in the United States. Two surveys are conducted. Of the 35 four-year colleges surveyed, the mean enrollment was 5,466 with a standard deviation of 8,191. Of the 35 two-year colleges surveyed, the mean enrollment was 5,068 with a standard deviation of 4,777. Test the student's claim at the 0.10 significance level.a) The null and alternative hypothesis would be: �0:��=��1:��>�� 0:��=��1:��≠�� 0:��=��1:��>�� 0:��=��1:��<�� 0:��=��1:��≠�� 0:��=��1:��<�� b) Determine the test statistic. Round to two decimals.�=c) Find the p-value and round to 4 decimals.p =
A student at a four-year college claims that mean enrollment at four-year colleges is higher than at two-year colleges in the United States. Two surveys are conducted. Of the 35 four-year colleges surveyed, the mean enrollment was 5,466 with a standard deviation of 8,191. Of the 35 two-year colleges surveyed, the mean enrollment was 5,068 with a standard deviation of 4,777. Test the student's claim at the 0.10 significance level. a) The null and alternative hypothesis would be: OHO: HF = HT H₁: HF HT O H₁: HF = HT H₁: PF PT t O Ho: PF = PT H₁: PF PT b) Determine the test statistic. Round to two decimals. c) Find the p-value and round to 4 decimals. p= d) Make a decision. O Reject the null hypothesis O Fail to reject the null hypothesis e) Write the conclusion. O There is not sufficient evidence to support the claim that enrollement is high at a four-year college than a two-year college. O There is sufficient evidence to support the claim that enrollement is high at a four-year…
A student at a four-year college claims that mean enrollment at four-year colleges is higher than at two-year colleges in the United States. Two surveys are conducted. Of the 35 four-year colleges surveyed, the mean enrollment was 5,466 with a standard deviation of 8,191. Of the 35 two-year colleges surveyed, the mean enrollment was 5,068 with a standard deviation of 4,777. Test the student's claim at the 0.10 significance level.a) The null and alternative hypothesis would be: �0:��=��1:��>�� 0:��=��1:��≠�� 0:��=��1:��>�� 0:��=��1:��<�� 0:��=��1:��≠�� 0:��=��1:��<�� b) Determine the test statistic. Round to two decimals.�=c) Find the p-value and round to 4 decimals.p =
Suppose babies born after a gestation period of 32 to 35 weeks have a mean weight of 2800 grams and a standard deviation of 900 grams while babies born after a gestation period of 40 weeks have mean weight of 3400 grams and a standard deviation of 445 grams. If a 33-week gestation period baby weighs 2625 grams and a 41-week gestation period baby weighs 3225 grams, find the corresponding z-scores. Which baby weighs less relative to the gestation period? Find the corresponding z-scores. Which baby weighs relatively less? Select the correct choice below and fill in the answer boxes to complete your choice. (Round to two decimal places as needed.) OA. The baby born in week 33 weighs relatively less since its z-score, OB. The baby born in week 33 weighs relatively less since its z-score, OC. The baby born in week 41 weighs relatively less since its z-score, OD. The baby born in week 41 weighs relatively less since its z-score, is smaller than the z-score of is larger than the z-score of is…
Pilots who cannot maintain regular sleep hours due to their work schedule often suffer from insomnia. A recent study on sleeping patterns of pilots focused on quantifying deviations from regular sleep hours. A random sample of 28 commercial airline pilots was interviewed, and the pilots in the sample reported the time at which they went to sleep on their most recent working day. The study gave the sample mean and standard deviation of the times reported by pilots, with these times measured in hours after midnight. (Thus, if the pilot reported going to sleep at p.m., the measurement was -1.) The sample mean was 0.8 hours, and the standard deviation was 1.6 hours. Assume that the sample is drawn from a normally distributed population. Find a 90% confidence interval for the population standard deviation, that is, the standard deviation of the time (hours after midnight) at which pilots go to sleep on their work days. Then give its lower limit and upper limit.
Twelve samples of coal from a Northern Appalachian source had an average mercury content of 0.253 ppm with a standard deviation of 0.029 ppm. Suppose the density of mercury content of coal from this source is approximately normally distributed. a. Find the LOWER bound of a 95% confidence interval for the mean mercury content of coal from this source. b. Find the UPPER bound of a 95% confidence for the mean mercury content of coal from this source.
For a random sample of 64 overweight men, the mean of the number of pounds that they were overweight was 30. The standard deviation of the population is 4.2 pounds. (a) Find the best point estimate for the average number of excess pounds for all overweight men. (b) Construct a 95% confidence interval of the mean of these pounds.
From a random sample of 48 days in a recent year, U.S. gasoline prices had a mean of $2.34 and a standard deviation of $0.32. Construct a 95% confidence interval for the population mean