Needing help on how to set up Solution1 We first get the z s

Needing help on how to set up .

Solution

1.

We first get the z score for the critical value. As z = (x - u) sqrt(n) / s, then as          
          
x = critical value =    20.26      
u = mean =    21.59      
n = sample size =    51      
s = standard deviation =    3.95      
          
Thus,          
          
z = (x - u) * sqrt(n) / s =    -2.40458223      
          
Thus, using a table/technology, the right tailed area of this is          
          
P(z >   -2.40458223   ) =    0.991904518 [answer]

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