Problem:
The Road King Tire Company in Birmingham wants to monitor the quality of the tires it manufactures. Each day the company quality-control manager takes a sample of 100 tires, tests them, and determines the number of defective tires. The results of 20 samples have been recorded below.
| Sample |
Number of
Defectives |
| 1 |
0 |
| 2 |
23 |
| 3 |
37 |
| 4 |
38 |
| 5 |
21 |
| 6 |
18 |
| 7 |
29 |
| 8 |
23 |
| 9 |
30 |
| 10 |
27 |
| 11 |
37 |
| 12 |
7 |
| 13 |
32 |
| 14 |
19 |
| 15 |
4 |
| 16 |
31 |
| 17 |
17 |
| 18 |
0 |
| 19 |
34 |
| 20 |
30 |
Required:
Question 1) What is the average percent defective for this data? 
Question 2) The corresponding p-chart for this process using 2?
Question 3) The corresponding p-chart for this process using 2?
Question 4) Is this process in control? yes/no
Solve the given numerical problem and illustrate step by step calculation.