3. A sociologist will conduct a two-sample t-test for a difference in means to investigate whether there is a significant difference, on average, between the salaries of people with bachelor's degrees and people with master's degrees. From a random sample of 32 people with a bachelor’s degree, the average salary was $55,000 with standard deviation $3,500. From a random sample of 28 people with a master's degree, the average salary was $58,000 with a standard deviation of $4,000. With a null hypothesis of no difference in the means, which of the following is the test statistic for the appropriate test to investigate whether there is a difference in population means (master's degree minus bachelor's degree) ? (58,000–55,000) t = 4,000 3,500 28 32 (58,000–55,000) t 4,0002, 3,5002 28 32 (58,000–55,000) t = 4,0002 3,5002 28 32 (58,000–55,000) 4,000+3,500 28+32 (58,000–55,000) E 4,0002 +3,5002 28+32

3. A sociologist will conduct a two-sample t-test for a difference in means to investigate whether there is a significant difference, on average, between the salaries of people with bachelor's degrees and people with master's degrees. From a random sample of 32 people with a bachelor’s degree, the average salary was $55,000 with standard deviation $3,500. From a random sample of 28 people with a master's degree, the average salary was $58,000 with a standard deviation of $4,000. With a null hypothesis of no difference in the means, which of the following is the test statistic for the appropriate test to investigate whether there is a difference in population means (master's degree minus bachelor's degree) ? (58,000–55,000) t = 4,000 3,500 28 32 (58,000–55,000) t 4,0002, 3,5002 28 32 (58,000–55,000) t = 4,0002 3,5002 28 32 (58,000–55,000) 4,000+3,500 28+32 (58,000–55,000) E 4,0002 +3,5002 28+32

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

2. A professional racing team is holding tryouts at its test track. The team requires its drivers to have an average lap time of at most 133 seconds at its test track. The team will use a one sample z-test of significance to determine if they should hire a new driver. An amateur driver completes 10 timed laps of the test track with an average lap time of 140 seconds. If the standard deviation of all lap times at this track is 4.5 seconds, what is the value of the test statistic? Round your answer to two decimal places. Answer value Please show work!!!
A union of restaurant and foodservice workers would like to estimate this year's mean hourly wage, u, of foodservice workers in the U.S. Last year's mean hourly wage was $8.08, and there is reason to believe that this year's value is different from last year's. The union decides to do a statistical test to see if the value has indeed changed. The union chooses a random sample of this year's wages, computes the mean of the sample to be $8.48, and computes the standard deviation of the sample to be $1.25. Based on this information, answer the questions below. What are the null hypothesis (H) and the alternative hypothesis (H,) that should be used for the test? H: u is [? |H: u is ? ? In the context of this test, what is a Type II error? A Type II error is ? v the hypothesis that u is ? when, in fact, u is ? Suppose that the union decides to reject the null hypothesis. What sort of error might it be making? ?
The president of an all-female school wants to know if the students at her school studied more or less, on average, than the students at a neighboring all-male school. To find out, she conducted a study. Accordingly, samples were taken at each school with the following results: All female: sample size = 43, mean study time ( hours) = 18.56, standard deviation (hours) = 4.35 All male: sample size = 38, mean study time (hours) =17.95, standard deviation (hours) = 4.87 Calculate the 95% confidence interval for the differences between population means. Use brackets write the final answer [x.xx, x.xx]
10. In a study conducted to determine the role that sleep disorders play in academic performance, researcher Jane Gaultney conducted a survey of 503 randomly selected students with a known sleep disorder (such as narcolepsy, insomnia, or restless leg syndrome) and found their mean GPA was 2.65 with a standard deviation of 0.87. Similarly, she randomly selected 1342 students with no known sleep disorders, and found their mean GPA to be 2.82 with a standard deviation of 0.83. You may assume that both population GPA's are normally distributed. Use a significance level of 0.05 to test whether the two groups have different mean GPA's. As a follow-up, construct and interpret a 95% confidence interval for the true difference in the mean GPA's of the two groups. What would be the type I and type II errors for this problem?
A. The salaries of pharmacy techs are normally distributed with a mean of $33,000 and a standard deviation of $4,000. If a pharmacy tech is selected at random, what is the probability they make more than $38,000? The answer should be typed as a decimal with 4 decimal places. B. The salaries of pharmacy techs are normally distributed with a mean of $33,000 and a standard deviation of $4,000. What is the minimum salary to be considered the top 6%? Round final answer to the nearest whole number. C. The average number of shoppers at a particular grocery store in one day is 505, and the standard deviation is 115. The number of shoppers is normally distributed. For a random day, what is the probability that there are between 250 and 450 shoppers at the grocery store? The answer should be typed as a decimal with 4 decimal places.
. The on-campus housing costs for a semester at a state university are Normally distributed with a mean of $1553 and a standard deviation of $329.(a) What is the distribution of the mean on-campus housing cost for a semester at this university for a random sample of 50 students? (b) What is the probability that a randomly selected on-campus student spends more than $1200 per semester? (c) What is the probability that a random sample of 50 students spends an average of less than $1500? (d) What is the probability that a random sample of 50 students spends an average of $1450 to $1600 per semester?
10
. A manufacturer of a new car claims the typical car will average 33 mpg of gasoline. An independent consumer group is skeptical of the claim and thinks the mean gas mileage is significantly different than the 33 claimed. A sample of 50 randomly selected cars produced a mean mpg of 31 with a standard deviation of 3.5. Assume that cars’ gas mileage is normally distributed in the population. ). a. The manufactures want to determine if the mean mpg for the cars is significantly different from 33. Write the null and alternative hypotheses for this question. b. What are the assumptions of this test? Are the assumptions met? ). C. Calculate and interpret the 95% confidence interval, and assess whether to reject the null hypothesis based on the interval. Use a t critical of 2.01.
asap
Records from the Washington Department of Licensing show that 47 former SFCC business students have incorporated their own businesses in the last five years. Eight of these students are selected at random and contacted. Each is asked how many people are employed by their corporation. The responses are: 7, 12, 13, 17, 10, 5, 10, and 6 employees. What is your best estimate of the standard deviation of the number of employees for all 47 corporations?
Community college instructors' salaries in one state are very low, so low that educators in that state regularly complain about their compensation. The national mean is $57,636$⁢57,636, but instructors from Mississippi claim that the mean in their state is significantly lower. They survey a simple random sample of 3737 colleges in the state and calculate a mean salary of $52,534$⁢52,534 with a standard deviation of $15,791$⁢15,791. Test the instructors' claim at the 0.050.05 level of significance. Step 3 of 3 : Draw a conclusion and interpret the decision.