Question

Please help ...medal and fan (:
A set of data has a normal distribution with a mean of 5.1 and a standard deviation of 0.9. Find the percent of data between 4.2 and 5.1.

Answer 1

You need to first calculate z scores for the lower limit of your interval:

z = (x - µ) / σ

= (4.2 - 5.1) / .9
= -.9 / .9
= -1.0

Then you need to look up z = -1 on a normal distribution table.

It shows that the proportion of cases falling between the mean and a z of -1 is .3413 or 34.13%

Answer 2

Okay got it thanks (:

Answer 3

My Pleasure.