Question 7.43

7.43 Another two-sample $t$ -test.

Refer to Exercise 7.41 (page 382).

Perform a significance test to see if there is a difference between the two sets of instructions using $α = 0.05$ .
Describe how you could use the 95% confidence interval you calculated in Exercise 7.41 to determine if the there is a difference between the two sets of instructions at significance level 0.05.

7.43

(a) $H_{0} : μ_{1} = μ_{2} .$ $H_{a} : μ_{1} \neq μ_{2}$ . (b) $d f = 9, 0.05 < P -value < 0.10$ $t = - 2.19.$ $d f = 9,$ $0.05 < P -value < 0.10$ . The data are not significant at the 5% level, and there is not enough evidence to show a difference between the two sets of instructions. (b) Because the confidence interval contains 0, we fail to reject $H_{0}$ .