Corrective maintenance tasks were observed as given in the table below

Task Time (min)	Frequency
35	2
17	6
12	2
15	4
37	1
27	10
33	3
31	6
25	12
19	10
21	12
23	13
29	8
13	3
9	1

1. What is the range of observations?
2. Assume 7 classes with a class interval width of four, plot the data and draw a curve. What type of distribution is indicated by the curve?
3. What is the mean repair time?
4. What is the standard deviation of the sample data?
5. The system is required to meet a mean repair time of 25 minutes at a stated confidence level of 95%. Do the data reveal that the specification requirements will be met? Why?