Answer:
a. μ = $24.57
μ ≠ $24.57
b. 0.12
c. we fail to reject the null hypothesis since p ≈0.12 > 0.05
d. we fail to reject the null hypothesis since z ≈-1.6 > -1.96
Step-by-step explanation:
a)
μ = $24.57
μ ≠ $24.57
b)
To compute p value, we need to calculate z-score of $23.89 per hour. in the distribution assumed under null hypothesis
z-score can be calculated as follows:
where
- X= $23.89
- M is the mean value under null hypothesis ( $24.57)
- s is the sample standard deviation ($2.40)
- N is the sample size (30)
Putting the numbers in the formula we get
≈ −1,5518
The corresponding p-value is <em>two tailed </em>and ≈ 0.12
c)
since p ≈0.12 > 0.05 <em>we fail to reject the null hypothesis.</em>
d)
Critical value for the 0.05 significance level in two tailed test is :
c(z)=-1.96 Since z≈ −1,6 >-1.96, it is not in the critcal region, therefore <em>we fail to reject the null hypothesis. </em>