Speedy net service is concerned that the level of access forcustomers is decreasing, as a result of heavier use. The proportionof peak period time when a customer’s download speed drops by 20percent or more below average time is considered a good measure ofservice level. The percentage of time a customer experiences suchdrops during peak periods varies. Using a sampling process, the ISPset up control charts to monitor the service level, based onproportion of below average download speed during peak periods.Construct the p-chart using the sample data in the table worksheetProb 07-07 in the ch07data.xlsx file on the student companion sitefor this chapter. What does the chart show? Is the service levelbased on the pchart data good or bad in your opinion?
| Peak | Number of | Number of |
| Period | Calls Attempted | Busy Signals |
| | |
| 1 | 492 | 8 |
| 2 | 424 | 9 |
| 3 | 508 | 4 |
| 4 | 614 | 5 |
| 5 | 566 | 11 |
| 6 | 616 | 6 |
| 7 | 528 | 5 |
| 8 | 382 | 8 |
| 9 | 608 | 8 |
| 10 | 506 | 5 |
| 11 | 596 | 3 |
| 12 | 510 | 9 |
| 13 | 428 | 11 |
| 14 | 524 | 8 |
| 15 | 410 | 3 |
| 16 | 586 | 9 |
| 17 | 488 | 8 |
| 18 | 618 | 3 |
| 19 | 552 | 9 |
| 20 | 466 | 10 |
| 21 | 472 | 6 |
| 22 | 484 | 2 |
| 23 | 468 | 8 |
| 24 | 574 | 8 |
| 25 | 606 | 7 |
| 26 | 620 | 7 |
| 27 | 575 | 5 |
| 28 | 600 | 8 |
| 29 | 541 | 5 |
| 30 | 393 | 4 |
