posted by Sally on .
A set of data is normally distributed with a mean of 16 and a standard deviation of 0.03. What percent of the data is between 15.2 and 16?
16-15.2 = 0.8
0.8/0.03 = n = 26 standard deviations
erf(n/sqrt(2)) = approximately 1
50% of the data would be between 15.2 and 16.
Are you sure there are no typos in your data?
If so, find the Z scores for both scores.
Z = (score-mean)/Standard deviation
In the back of your stat text, find the Z scores in a table labeled something like "areas under the normal distribution." Find the proportion between the two scores and convert to a percentage.