A mean score on a standardized test is 50 with a standard deviation of 10. Answer the following

a. What scores fall between –1 and +1 standard deviation?
b. What percent of all scores fall between –1 and +1 standard deviation?
c. What score falls at +2 standard deviations?
d. What percentage of scores falls between +1 and +2 standard deviations?

IF THERE IS A FORMULA CAN YOU PROVIDE IT.

2 answers

Z = (score-mean)/SD

Z = raw scorre interms of standard deviations.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores. Insert into equation above.
What percentage of scores falls between +1 and +2 standard deviations?