A normally distributed population has a mean of 80 and stand
A normally distributed population has a mean of 80 and standard deviation of 20.
Calculate the z-score value for the following sample means and sample sizes.
(a) =
(b) =
(c) =
(d) =
(e) =
(f) =
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| Population Mean | = 80 | 
| Population Standard Deviation | ? = 20 | 
Solution
(a) s/vn= 20/sqrt(4) =10
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(b) Z-score= (X-mu)/(s/vn)
=(90-80)/10
=1
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(c)20/sqrt(25) = 4
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(d)(84-80)/4 =1
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(e)20/sqrt(100) = 2
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(f)(50-80)/2 =-15

