Question

example 10.12
a college softball coach was interested in whether the colleges strength development class increased their players maximum lift (in pounds). four players participated in the study. the amount of weight they could each lift was recorded before they took the strength development class. after completing the class, the amount of weight they could each lift was again measured. the data are as follows:
table 10.17

• write null and alternative hypotheses. is this one or two - tailed test?

Explanation:

Step1: Define the null hypothesis

The null hypothesis \(H_0\) assumes no change. Let \(\mu_d\) be the mean difference (after - before). \(H_0:\mu_d = 0\)

Step2: Define the alternative hypothesis

The coach is interested in if the class increased the lift. So \(H_1:\mu_d> 0\)

Step3: Determine the tail - type

Since the alternative hypothesis is \(H_1:\mu_d>0\) (looking for an increase), it is a one - tailed test.

Answer:

Null hypothesis \(H_0:\mu_d = 0\), alternative hypothesis \(H_1:\mu_d>0\). It is a one - tailed test.