Answer:
We use z-test for this hypothesis.

Explanation:
We are given the following in the question:
Population mean, μ = 4.88
Sample mean,
= 5.91
Sample size, n = 48
Alpha, α = 0.05
Population standard deviation, σ = 3.2
First, we design the null and the alternate hypothesis

The null hypothesis states that the mean score of successful managers on a psychological test is 4.88 and the alternate hypothesis says that the mean score of successful managers on a psychological test is greater than 4.88.
We use One-tailed z test to perform this hypothesis.
Formula:

Putting all the values, we have
