The expression that can be used is 3.14 (6x4+6^2)
The surface area is 188.4
Answer: A. We are 99% confident that the interval from 4.1 to 5.6 actually does contain the true value of mu.
Step-by-step explanation:
The correct interpretation of a 99% confidence interval is that we are 99% confident that the true population mean falls in it.
Given 99% confidence interval : 
Then, the correct interpretation : We are 99% confident that the interval from 4.1 to 5.6 actually does contain the true value of mu.