Question

The heights of people in the country Lilliput are Normally distributed with a mean of 88 cm and a standard deviation of 11 cm. Fill in the blank showing how you obtain your answer: 77% of people in Lilliput are over __________ cm tall.

Answer 1

Solution :

Given that,  

mean = = 88

standard deviation = = 11

Using standard normal table ,

P(Z > z) = 77%

1 - P(Z < z) = 0.77

P(Z < z) = 1 - 0.77

P(Z < -0.74) = 0.23

z = -0.74

Using z-score formula,

x = z * +

x = -0.74 * 11 + 88 = 79.86

77% of people in Lilliput are over 79.86 cm tall