7.11 Consider a population of 250 with a mean of 60 and a standard deviation equal to 23. What is the probability of obtaining a sample mean of 62 or less with a sample size of 45?

Solution:

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What is the probability of obtaining a sample mean of 62 or less with a sample size of 45?

???? x=o/(n)((N -n)/(N - 1))

What is the probability of obtaining a sample mean of 62 or less with a sample size of 45?

???? x= 23/45= 23/(6.708)=3.43

z62=(x -)/( o)=(62-60)/3.43=2/3.43=.58

P( x62) = .7190

Is this correct?