How to solve for X with a mean = 9, deviation = 3 and a sample...

How to solve for X with a mean = 9, deviation = 3 and a sample size of 25, P( sample mean > 8) is

Expert Solution

Population mean, µ =    9
Population standard deviation, σ =    3
Sample size, n =    25

P( x̅ > 8)
= P( (x̅-μ)/(σ/√n) > ( 8 - 9 )/(3/√25 ) )
= P( z > -1.6667 )
= 1 - P( z < -1.6667)
Using excel function:
= 1- NORM.S.DIST( -1.6667 , 1)
= 0.9522

orchestra answered 3 years ago

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