Question

The human resources department of a consulting firm gives a standard creativity test to a randomly selected group of new hires every year. This year, 60 new hires took the test and scored a mean of 112.8 points with a standard deviation of 13.8. Last year, 75 new hires took the test and scored a mean of 117.2 points with a standard deviation of 16.8. Assume that the population standard deviations of the test scores of all new hires in the current year and the test scores of all new hires last year can be estimated by the sample standard deviations, as the samples used were quite large.

Answer 1

Construct a 95% confidence interval for μ1-μ2, the difference between the mean test score μ1 of new hires from the current year and the mean test score μ2 of new hires from last year. Then complete the table below.

What is the lower limit of the 95% confidence interval?
What is the upper limit of the 95% confidence interval?

Answer 2

i cant read the type

Answer 3

oh wow.. thats \[\mu1-\mu2\]

Answer 4

basically wherever the question marks are, the mu symbol is supposed to be there.

Answer 5

ok

Answer 6

are these multiple choice questions

Answer 7

so mu1 - mu2 is -4.4

Answer 8

no they aren't :(

Answer 9

Could I do this like the last one, and just find the confidence intervals of them individually and then average them?

Answer 10

theres a formula

Answer 11

i am reading this http://onlinestatbook.com/2/estimation/difference_means.html

Answer 12

do you know if your answers are correct or not?

Answer 13

no :(

Answer 14

gonna use the restroom, brb