Answer:
There is not sufficient sample evidence to support the claim that the population mean is not equal to 88.9.
Explanation:
We are given the following hypothesis below;
Let
= population mean.
So, Null Hypothesis,
:
= 88.9 {means that the population mean is equal to 88.9}
Alternate Hypothesis,
:
88.9 {means that the population mean is different from 88.9}
The test statistics that will be used here is One-sample t-test statistics because we don't know about population standard deviation;
T.S. =
~

where,
= sample mean = 81.3
s = sample standard deviation = 13.4
n = sample size = 7
So, the test statistics =
~

= -1.501
The value of t-test statistics is -1.501.
Also, the P-value of the test statistics is given by;
P-value = P(
< -1.501) = 0.094
Since the P-value of our test statistics is more than the level of significance as 0.094 > 0.01, so we have insufficient evidence to reject our null hypothesis as the test statistics will not fall in the rejection region.
Therefore, we conclude that the population mean is equal to 88.9.