Answer:
We reject the null hypothesis.
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 71
Alpha, α = 0.08
Population variance is known.
First, we design the null and the alternate hypothesis
[tex]H_{0}: \mu = 20\\H_A: \mu > 20[/tex]
We use One-tailed z test to perform this hypothesis.
Formula:
[tex]z_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{\sigma}{\sqrt{n}} }[/tex]
a) We calculate the z-critical with the help of z-table.
[tex]z_{critical} \text{ at 0.08 level of significance } = 1.41[/tex]
b)
[tex]z_{stat} = 1.56[/tex]
Since,
[tex]z_{stat} > z_{critical}[/tex]
We fail to accept the null hypothesis and reject the null hypothesis and accept the alternate hypothesis.