10.11Homework

NCSS

10.11Homework

Using formulas

€

t* =(x 1 − x 2) − (μ1 −μ2)

Sp2(1

n1+1

n2)

=(234.655 − 303.13) − (0)

5952.7(1

29+1

16)

= −2.85

Sp2 =(n1 −1)S1

2 + (n2 −1)S22

(n1 −1) + (n2 −1)=28(49.21)2 +15(112)2

43= 5952.7

newspapernot newspaper

Above 50Younger

12.18

12.24

H0: stress level is independent of commuting timeH1: there is a relationship between stress level and commuting time

There is not enough evidence to conclude that there is a significant relationship between commuting time and stress level at the 0.01 level of significance.

However, there is enough evidence to conclude that there is a significant relationship between commuting time and stress level at the 0.05 level of significance.

Since the pvalue is fairly small 0.043, we could be fairly confident in concluding there is a relationship (dependence) between the commuting time of company employees and the level of stress-related problems observed on the job.

13.04

For a 1 square foot increase in shelf space, estimated weekly sales increases by 7.40 dollars.

Yhat (when X=8) is $204.2Predicted weekly sales for pet food with shelf space of 8 feet is $204.20.