Carry your intermediate computations to at least four decima

Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places.

Solution

We first get the z score for the critical value. As z = (x - u) sqrt(n) / s, then as          
          
x = critical value =    2.05      
u = mean =    2.3      
n = sample size =    40      
s = standard deviation =    0.8      
          
Thus,          
          
z = (x - u) * sqrt(n) / s =    -1.976423538      
          
Thus, using a table/technology, the right tailed area of this is          
          
P(z >   -1.976423538   ) =    0.975946586