Answer:
Yes, there is a significant difference in customer satisfaction ratings at the two stores
The P-value is P=0.000.
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>The store A has a sample mean of 4.05 and a sample standard deviation of 0.039. The store B has a sample mean of 3.99 and a sample standard deviation of 0.025.</em>
We have to perform an hypothesis test for the difference between means.
The claim will state that satisfaction ratings differ. So, the null and alternative hypothesis are:
being μ1: the actual staisfaction rating of store A, and μ2: the actual satisfaction rating of store B.
The significance level is 0.05.
We know that, for both samples, the sample size is n=100.
The difference between means is:
The standard error of the diffence between means is calculated as:
The z-statistic can be calculated as:
The P-value for this test statistic in a two tailed test is
The P-value is smaller than the significance level, so the effect is significant. The null hypothesis is rejected.
There is enough evidence that the customer satisfaction rating differs from store A to store B.