With a mean of 100 and a standard deviation of 20 what raw s

With a mean of 100 and a standard deviation of 20, what raw score would fall at the 27th percentile?

Solution

P( z < z ) = 0.27

using tables we have a value of z for a p value of 0.27

since is below of 0.5 the z vcalue will be negative

z = -0.61

-0.61 = ( x - 100 ) / 20

x = 87.8

what raw score would fall at the 27th percentile?

87.8 is the answer