Answer:
a) H0: 
H1: 
n = 13 represent the sample size
represent the calculated statistic
The degrees of freedom are given by:

We can calculathe the p value with this formula:

Since
we fail to reject the null hypothesis on this case at 5% of significance.
b) H0: 
H1: 
n = 13 represent the sample size
represent the calculated statistic
The degrees of freedom are given by:

We can calculathe the p value with this formula:

Since
we fail to reject the null hypothesis on this case at 5% of significance.
c) H0: 
H1: 
n = 25 represent the sample size
represent the calculated statistic
The degrees of freedom are given by:

We can calculathe the p value with this formula:

Since
we can reject the null hypothesis on this case at 1% of significance.
Step-by-step explanation:
Part a
For this case we assume that we are testing the following system of hypothesis
H0: 
H1: 
n = 13 represent the sample size
represent the calculated statistic
The degrees of freedom are given by:

We can calculathe the p value with this formula:

Since
we fail to reject the null hypothesis on this case at 5% of significance.
Part b
For this case we assume that we are testing the following system of hypothesis
H0: 
H1: 
n = 13 represent the sample size
represent the calculated statistic
The degrees of freedom are given by:

We can calculathe the p value with this formula:

Since
we fail to reject the null hypothesis on this case at 5% of significance.
Part c
For this case we assume that we are testing the following system of hypothesis
H0: 
H1: 
n = 25 represent the sample size
represent the calculated statistic
The degrees of freedom are given by:

We can calculathe the p value with this formula:

Since
we can reject the null hypothesis on this case at 1% of significance.