Test for normality using alpha 005 what inferences can you

Question

The waiting time in minutes before being served in a local post office is observed for 50 randomly chosen customers:

(a) Test for normality using α= 0.05. What inferences can you draw?

(b) Estimate the mean and standard deviation of the waiting times.

(c) If the goal of the post office is for the waiting time not to exceed 4 minutes, find the capability indices CPU and C_pk and comment on these values. Assuming normality, what proportion of the customers, if any, will have to wait for more than 4 minutes?

2.1     0.5     3.6     1.4     2.0     1.9     2.4     2.7     2.1     1.8
0.8     0.4     4.2     3.5     2.5     4.6     3.8     1.5     4.5     3.9
4.8     2.8     1.9     1.2     3.2     5.5     2.5     3.8     5.0     4.6
1.6     2.5     2.4     1.9     2.0     2.1     2.8     1.6     3.8     4.2
3.5     5.2     3.1     1.6     1.5     3.5     5.2     4.8     3.9     2.6