The number of pounds gained during pregnancy are normal with mean=30.23 and st. deviation=13.84
Determine the percent of women that gain between 20 and 30 pounds.
You have to subtract the mean from each score and divide by the standard deviation.
This will give you two z-scores
One for (20 -30.23)/13.84
the other one (30 - 30.23)/13.84
Use a standard z (normal table) to find the area under the curve between these two numbers. That will give you the percent of women in that range.posted by Dr. Jane