a sample of size 36 from a normally distributed population variable with population standard deviation 20 had a sample mean of 88. find a 99% confidence interval for the population mean.

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm