Hypothesized population mean (µ0) : 3.5

Sample Mean (X bar) 2.75

Standard deviation (of population or sample) 0.65

Sample size (n) 50

Confidence level % 95

Use one sample Z test calculator template with these values to do the hypothesis test

Null Hypothesis Mu = 3.5

We have to prove that the mean turn around time is reduced?

Hence it is a Left Tailed Test

Alternate Hypothesis Mu<3.5

Z Computed value should be greater than Z critical Value for Null Hypothesis to be true

Please see attached file for complete solution.