Answer:
The probability that they have a mean height greater than 71.9 inches
P( x⁻ ≥71.9) = 0.0022
Step-by-step explanation:
Explanation:-
Given mean of the Population μ= 70.9
Standard deviation of the Populationσ = 2.1
Given sample size 'n' =36
let x⁻ be the mean height
given x⁻ =71.9 inches
[tex]Z=\frac{x^{-} -mean}{\frac{S.D}{\sqrt{n} } }[/tex]
[tex]Z=\frac{71.9 -70.9}{\frac{2.1}{\sqrt{36} } } = \frac{1}{0.35} = 2.85[/tex]
The probability that they have a mean height greater than 71.9 inches
P( x⁻ ≥71.9) = P(Z ≥ 2.85)
= 1 - P(Z≤ 2.85)
= 1 - ( 0.5 + A(2.85)
= 0.5 - A( 2.85)
= 0.5 - 0.4978
= 0.0022
The probability that they have a mean height greater than 71.9 inches
P( x⁻ ≥71.9) = 0.0022
