Standard Deviation

Question

I have no idea how to begin going about this question.

If the mean score on a test is 77 and the Standard Deviation is 8, what is the % of scores above and below 88?

I found the Z-score (1.375) so I know that 88 is 1.375 standard deviations above the mean, but I don't know how to go from here. Please help!

Answer 1

Just look up your z-score in a z-score table. It'll give you the percent (as a decimal) that scored 88 or less. So the percent that scored 88 or more is just 100% - (% that scored 88 or less). If you don't have a z-table, you can find them on line.