Question

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

Answer 1

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