The scores on a psychology exam were normally distributed with a mean of 67 and a standard deviation of 7. What is the standard score for an exam score of ​70?

Answer 1

z = (70-67)/7 = -3/7

use z tables or a z calculator to find the area under the curve for z<-3/7 = about 0.429

standard score = the percentile = about 66.6%

you passed with a D, if this is on June 6th, 6/6 it's D Day, very appropriate

by the empirical rule if z had been 1, then the percentile would have been: .5 +.68/2 = .5+34 = .84 = 84%

so for z= about .429, 50% < percent < 84%

midpoint is 134/2 = 67% = about 66.6%