Probability word problem

• May 23rd 2008, 02:54 PM
~berserk
Probability word problem
A shoe manufacturer collects data regarding men's shoe sizes and found that the distribution of sizes exactly fits the normal curve. If the mean of the shoe sizes is 11 and the standard deviation is 1.5 find:

a.) the probability that a man's shoe size is greater than or equal to 11

b.) the probability that a man's shoe size is greater than or equal to 12.5
• May 23rd 2008, 03:12 PM
mr fantastic
Quote:

Originally Posted by ~berserk
A shoe manufacturer collects data regarding men's shoe sizes and found that the distribution of sizes exactly fits the normal curve. If the mean of the shoe sizes is 11 and the standard deviation is 1.5 find:

a.) the probability that a man's shoe size is greater than or equal to 11

b.) the probability that a man's shoe size is greater than or equal to 12.5

a) Pr(X > 11) ....... you should be able to do in 1 second flat without any table or technology ...... What was the mean again .....?

b) Pr(X > 12.5) = Pr(X > 11 + 1.5) ...... Hmmmmm ... one standard deviation away from the mean ......