Consider the following data that represents a random sample
Consider the following data that represents a random sample out of a very large population:
 0.43, 4.89, 5.29, 5.16, 0.59, 7.50, 4.48, 6.22
Regardless of your answer to (a), assume the population distribution is normal and use that fact to
 create a 90% CI for µ.
Solution
Note that              
               
 Lower Bound = X - z(alpha/2) * s / sqrt(n)              
 Upper Bound = X + z(alpha/2) * s / sqrt(n)              
               
 where              
 alpha/2 = (1 - confidence level)/2 =    0.05          
 X = sample mean =    4.32          
 z(alpha/2) = critical z for the confidence interval =    1.644853627          
 s = sample standard deviation =    2.528816776          
 n = sample size =    8          
               
 Thus,              
               
 Lower bound =    2.849382847          
 Upper bound =    5.790617153          
               
 Thus, the confidence interval is              
               
 (   2.849382847   ,   5.790617153   ) [ANSWER]

