Question

The mean height of women in a country​ (ages

20minus−​29)

is

64.3

inches. A random sample of

65

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

65

​inches? Assume

sigmaσequals=2.69

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

65

inches is

Answer 1

Solution :

Given that,

mean = = 64.3

standard deviation = = 2.69

= =64.3

= / n = 2.69/ 65= 0.33

P( >65 ) = 1 - P( <65 )

= 1 - P[( - ) / < (65-64.3) /0.33 ]

= 1 - P(z < 2.12)

Using z table

= 1 - 0.9830

= 0.0170

probability= 0.0170