Answer: The critical value using the t-table at 0.05 level of significance is 2.306.
Explanation:
Since we have given that
n = 9
We will use t- test as n < 30.
so, the degree of freedom v = n-1 = 9-1 = 8
Now, α = 0.05
According to t-table, we get that

Hence, the critical value using the t-table at 0.05 level of significance is 2.306.