The diameter of a brand of PingPong balls is approximately n

The diameter of a brand of Ping-Pong balls is approximately normally distributed with a mean of 1.31 inches and a standard deviation of 0.04 inch. A random sample of 4 ping

Solution

X: diameter of ping pong balls

X follows normal distirbution with mean 1.31 and var 0.0.4² /4.

Now use NORMDIST function in excel with mean 1.31 and sd 0.02

we get 0.15865.