1. Normal distribution problem

height of students is normally distributed

Mean = 67
standard deviation = 4

what portion of students that are over 67 inches tall are also under 70 inches tall?

I get a z value of .5 for 67 inches and .9332 for 70 inches

If I simply divide the z value of .9332 by .5 I get 1.8664, which is obviously wrong because it is more than 1.

(.9332 - .5000) / .5000

= 8664?

2. Re: Normal distribution problem

Hey krd16432.

If I read this correctly, you are looking for P(67 < X < 70) = P(X < 70) - P(X < 67). You have calculated these values above so the next step is to plug them in.