Is there statistical evidence that the average number of cases solved per month differs at a significance level of 0.05?

What can you say about the P-value?

Construct a 95% confidence interval for the mean difference in cases solved.

A) do you just run a test for a population mean for both detectives and compare if they fall in the signifigance level?

B)would you say P(>1.645) as the significance level is a 90% confidence interval?

C) I understand how to obtain the range; however, what is the mean difference? Is it 4.0 - 3.5 = 0.5?