find the specific percentiles using the sample in data set c

Find the specified percentiles using the sample in Data Set C: Data Set C Do this item \"by hand\" using the method in our text. Post your results on the Excel Answer Sheet 41 25 71 50 72 76 109 7a 7b 7c 7d Value of x at the Value of x at the Value of x at the Value of x at the 13 77 25 90 percentile percentile percentile percentile 18

Solution

a) mean = 58.67

std dev = 26.65

a) P(X < x) = 0.13

P(Z < (x - 58.67)/26.65 ) = 0.13

or, (x - 58.67)/26.65 = -1.13

or, x = 28.5555

b) P(X < x) = 0.77

P(Z < (x - 58.67)/26.65 ) = 0.77

or, (x - 58.67)/26.65 = 0.74

or, x = 78.391

c) P(X < x) = 0.25

P(Z < (x - 58.67)/26.65 ) = 0.25

or, (x - 58.67)/26.65 = -0.67

or, x = 40.8145

d)P(X < x) = 0.9

P(Z < (x - 58.67)/26.65 ) = 0.9

or, (x - 58.67)/26.65 = 1.28

or, x = 92.782