Answer:
Correct option: b 39.
Step-by-step explanation:
A one-sample (or one mean) t-test is applied to test whether the population-parameter is significantly different from some hypothetical value.
The degrees of freedom of the t-test is:
df = n - 1
It is provided that the sample size is, n = 40.
Compute the degrees of freedom as follows:
df = n - 1
= 40 - 1
= 39
Thus, the correct option is b.
