Question

A study was conducted to estimate the effect of college student employment on academic performance. In...

A study was conducted to estimate the effect of college student employment on academic performance. In a random sample of 15 working students, the mean GPA was 2.4 with a standard deviation of 0.05. In a random sample of 13 nonworking students, the mean GPA was 2.3 with a standard deviation of 0.03. Assume the populations are normal with equal variances. Round your critical value to three decimals.

Enter your answers rounded to four decimal places.

(a). The pooled sample variance is:  

(b). Using your answer in part (a), construct a 99% confidence interval for μW−μNW, the mean difference in GPA between working and nonworking students

Lower bound =   and Upper bound =

(c). Which of the following does your data suggest?

A) Working students have a lower GPA on average

B) Nonworking students have a lower GPA on average

C) Working and nonworking students have same GPA on average

Homework Answers

Answer #2

The statistical software output for this problem is:

Hence,

a) Pooled sample variance = 0.0018

b) Lower bound = 0.0558

Upper bound = 0.1442

c) Nonworking students have a lower GPA on average

answered by: anonymous
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
In a study of the effect of college student employment on academic performance, the following summary...
In a study of the effect of college student employment on academic performance, the following summary statistics for GPA were reported for a sample of students who worked and for a sample of students who did not work. The samples were selected at random from working and nonworking students at a university. (Use a statistical computer package to calculate the P-value. Use μemployed − μnot employed. Round your test statistic to two decimal places, your df down to the nearest...
In a study of the effect of college student employment on academic performance, the following summary...
In a study of the effect of college student employment on academic performance, the following summary statistics for GPA were reported for a sample of students who worked and for a sample of students who did not work. The samples were selected at random from working and nonworking students at a university. (Use a statistical computer package to calculate the P-value. Use ?employed ? ?not employed. Round your test statistic to two decimal places, your df down to the nearest...
The student academic group on a college campus claims that freshman students study at least 2.5...
The student academic group on a college campus claims that freshman students study at least 2.5 hours per day, on average. One Introduction to Statistics class was skeptical. The class took a random sample of 30 freshman students and found a mean study time of 137 minutes with a standard deviation of 45 minutes. If α = 0.01 (or 99% confidence level), is the student academic group’s claim correct?
A study in the Journal of Leisure Research investigated the relationship between academic performance and leisure...
A study in the Journal of Leisure Research investigated the relationship between academic performance and leisure activities. Each in a sample of 159 high school students was asked to state how many leisure activities they participated in weekly. From the list, activities that involved reading, writing, or arithmetic were labeled "academic leisure activities." Some of the results are listed below: Mean Standard Deviation GPA 2.96 0.71 Number of leisure activities 12.38 5.07 Number of academic leisure activities 2.77 1.97 Knowing...
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their...
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their drinking including missing class, falling behind, doing poorly on exams or papers, and receiving lower grades overall.” A statistics student is curious about drinking habits of students at his college. He wants to estimate the mean number of alcoholic drinks consumed each week by students at his college. He plans to use a 90% confidence interval. He surveys a random sample of 62 students....
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their...
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their drinking including missing class, falling behind, doing poorly on exams or papers, and receiving lower grades overall.” A statistics student is curious about drinking habits of students at his college. He wants to estimate the mean number of alcoholic drinks consumed each week by students at his college. He plans to use a 90% confidence interval. He surveys a random sample of 65 students....
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their...
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their drinking including missing class, falling behind, doing poorly on exams or papers, and receiving lower grades overall.” A statistics student is curious about drinking habits of students at his college. He wants to estimate the mean number of alcoholic drinks consumed each week by students at his college. He plans to use a 95% confidence interval. He surveys a random sample of 60 students....
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their...
According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their drinking including missing class, falling behind, doing poorly on exams or papers, and receiving lower grades overall.” A statistics student is curious about drinking habits of students at his college. He wants to estimate the mean number of alcoholic drinks consumed each week by students at his college. He plans to use a 90% confidence interval. He surveys a random sample of 62 students....
A marketing study was conducted to compare the mean age of male and female purchasers of...
A marketing study was conducted to compare the mean age of male and female purchasers of a certain product. Random and independent samples were selected for both male and female purchasers of the product. It was desired to test to determine if the mean age of all female purchasers exceeds the mean age of all male purchasers. The sample data is shown here: Female: n = 10, sample mean = 50.30, sample standard deviation = 13.215 Male: n = 10,...
A student researcher compares the heights of American students and non-American students from the student body...
A student researcher compares the heights of American students and non-American students from the student body of a certain college in order to estimate the difference in their mean heights. A random sample of 12 American students had a mean height of 67.9 inches with a standard deviation of 2.08 inches. A random sample of 18 non-American students had a mean height of 64 inches with a standard deviation of 1.62 inches. Determine the 99 % confidence interval for the...