M.Com. (Semester III) (CBCS) Examination Nov/Dec-2018
ADVANCED STATISTICS (Paper III)
Industrial Statistics
Time: 2½ Hours Max. Marks: 70
Instructions: All questions are compulsory.
Figures to the right indicate full marks.
Use of calculator is allowed.
Graph papers will be supplied on request.
Q.1 Choose the alternatives given below. 14
The general theory of control charts was first developed by
Fisher Gauss
Shewhart Deming
The horizontal line in the control chart which shows the minimum value of
quality characteristic before process gets out-of-control is called as
UCL LCL
Desired value CL
A process is said to be in the statistical control if it operates with
chance causes assignable causes
both neither nor
What will be the value of 3-sigma upper control limit for c chart when
standard is given?
UCL C 3 C C 2 C
UCL C C C 3 C
Process control is carried out
before production after production
during production all the above
The type of inspection that classifies items as defective or non-defective is
variable inspection attribute inspection
fixed inspection all the above
In the construction of p chart, it is assumed that the number of defectives has
distribution.
normal binomial
poisson geometric
A curve showing the probability of accepting a lot of quality p is known as
AOQ curve ASN curve
OC curve ATI curve
The quality level which the consumer regards as rejectable is called
Lot tolerance percent defective (LTPD)
Rejectable Quality Level
Producer's risk
Consumer's risk
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SLR-CS-29
10) Probability of rejecting a lot of sufficient good quality is known as
Producer's risk Consumer's risk
Both Neither nor
11) The control chart used to monitor process variability is
mean chart range chart
p chart c chart
12) The variation due to assignable causes in the product occurs due to
faulty process carelessness of operators
poor quality of raw material all the above
13) Which among the following is a type of control chart for variables?
Range chart p chart
np chart all the above
14) A defective item has at least defects.
4 3
2 1
Q.2 Explain the causes of variation in quality of manufactured product. 07
What do you mean by specification limits and control limits? 07
Q.3 Distinguish between variable and attribute control charts. 07
Explain the terms
1. Consumer's risk
2. Producer's risk
07
Q.4 Attempt any one of the following. 14
Discuss various steps involved in the construction of X and R charts. Sample
of 5 are taken from a manufacturing process and certain quality characteristic
is measured. The X and R values are computed for each sub-group. After 20
sub-groups, X 0.87632 and R 0.2410
Compute the control limits for the X and R charts.
(Given for n A2 0.58, D3 0 and D4 2.11)
OR
What is Statistical Quality Control Explain the need of SQC in
industrial sector.
Q.5 Attempt any one of the following. 14
Discuss the theroretical basis of p and np charts. Given that process fraction
defective is 0.2 and n is 25. Calculate the control limits for p and np charts.
OR
Explain the construction of control chart for number of defects. The number of
defects in 20 pieces of cloth each of 100 meters length is given below:
10, 5
Draw the control chart for number of defects.