mean 200 standard deviation 10 , selected 9 pepoople , find the probability that their sample mean will be larger than 207.7

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?

Which of the following will form the composite function?

Meee i honestly dont know what this question talking about