The numbers 360 and 400, written as the product of its prime factors, are 360 = 3 2 x 2 3 x 5 400 = 2 4 x5 2
a) Using the fact 400 = 2 4 x5 2 , find the square root of 400.

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500