# Statistical Quality Control-Control Charts (ISS (Statistical Services) Statistics Paper IV): Questions 17 - 20 of 31

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 92 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 350.00 or

How to register?

## Question number: 17

» Statistical Quality Control » Control Charts » Variable

Essay Question▾

### Describe in Detail

a) If the average range for the 4 samples is 0.2 millimeters and the average mean of the observations is 12.5 millimeters, obtain the three-sigma control limits for the sample mean.

b) 5 observations have been taken from the10 samples in order to test the volume in the bags. The average sample range is 0.5 ounces. Obtain the 3-σ limits for the sample range.

### Explanation

a) It is given that n = 5 and

For n = 5, The value of

Control limits for :

And

b) We are given that, number of observations, n = 5,

For n = 5, from the tables we have,

Control limits

… (160 more words) …

## Question number: 18

» Statistical Quality Control » Control Charts » Variable

Essay Question▾

### Describe in Detail

A new oven has been installed in a bakery and to test the efficiency of this, the oven temperature readings have been taken at four different places inside the oven every 30 min. The following table gives readings. Determine the control limits for the mean temperature.

 Time Readings 8: 00 400 500 550 390 8: 30 440 420 380 380 9: 00 410 450 470 430 9: 30 390 390 410 410 10: 00 370 420 460 410 10: 30 390 400 390 400

### Explanation

 Readings Total Sample mean Sample Range 400 500 550 390 1840 460 160 440 420 380 380 1620 405 60 410 450 470 430 1760 440 60 390 390 410 410 1600 400 20 370 420 460 410 1660 415 90 390 400 390 400 1580 395 10 Total 2515 400

… (14 more words) …

## Question number: 19

» Statistical Quality Control » Control Charts » Attributes

Essay Question▾

### Describe in Detail

The following are the figures of defectives in 22 lots each containing 2,000 bulbs. Ind control limit for p-Chart.

 425 430 216 341 225 322 280 306 337 305 356 402 216 264 126 409 193 326 280 389 451 420

### Explanation

We have n = 2000

 S. No. d 1 425 0.2125 2 430 0.215 3 216 0.108 4 341 0.1705 5 225 0.1125 6 322 0.161 7 280 0.14 8 306 0.153 9 337 0.1685 10 305 0.1525

… (79 more words) …

## Question number: 20

» Statistical Quality Control » Control Charts » Attributes

Essay Question▾

### Describe in Detail

Each day a sample of 1500 items from a production process was examined. The number of defectives found in each sample was as follows. With a suitable control chart, check out for control 4,6, 6,2, 15,4, 4

### Explanation

We have n = 30

 S. No. d 1 4 0.00267 2 6 0.00400 3 6 0.00400 4 2 0.00133 5 15 0.01000 6 4 0.00267 7 4 0.00267 Total 41 0.02733

Cont

… (71 more words) …