Question

The mean height of women in a country​ (ages

20minus−​29)

is

63.8

inches. A random sample of

55

women in this age group is selected. What is the probability that the mean height for the sample is greater than

64

​inches? Assume

sigmaσequals=2.65.

The probability that the mean height for the sample is greater than

64

inches is

Answer 1

Solution :

Given that ,

mean = = 63.8

standard deviation = = 2.65

n = 55

= 63.8

= / n = 2.65/ 55= 0.3573

P( >64 ) = 1 - P( < 64)

= 1 - P[( - ) / < (64 -63.5) / 0.3573]

= 1 - P(z <0.56 )

Using z table

= 1 - 0.7123

= 0.2877

probability=0.2877