PSG College of Technology, Coimbatore - 641 004 Semester Examinations, Semester
PSG College of Technology, Coimbatore - 641 004 Semester Examinations, Semester
PSG College of Technology, Coimbatore - 641 004 Semester Examinations, Semester
11221518
Roll No:
(To be filled in by the candidate)
INSTRUCTIONS:
1. Answer ALL questions from PART - A and Answer any FOUR questions from PART -
B. Question under PART - C is Compulsory.
2. Statistical tables are permitted
PART - A Marks : 10 x 3 = 30
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Qp No. 11221518
12. a. A filling machine is expected to fill 5Kg of powder into bags. A sample of 10 bags
gave the weights 4.7, 4.9, 5.0, 5.1, 5.4, 5.2, 4.6, 5.1, 4.6 and 4.7. Test whether the
machine is working properly. (6.5)
b. A large hotel chain is trying to decide whether to convert more of its rooms to
nonsmoking rooms. In a random sample of 400 guests last year, 166 had requested
nonsmoking rooms. This year, 205 guests in a sample of 380 preferred the
nonsmoking rooms. Would you recommend that the hotel chain convert more rooms
to nonsmoking? Support your recommendations by testing the appropriate hypothesis
at a 0.01 level of significance. (6)
13. a. In the manufacture of precision pins in which the diameter of the pin is the quality
characteristic to be controlled, 10 samples of 5 pins each were collected after a lapse
of every 30 minute period. X and R for each sample was calculated and the results
were recorded as below.
Sample 1 2 3 4 5 6 7 8 9 10
No.
X 50.04 50.24 50.14 50.08 50.28 50.16 50.30 50.10 50.16 50.10
R 0.07 0.08 0.03 0.05 0.04 0.09 0.04 0.04 0.05 0.07
PART - C Marks : 1 x 20 = 20
16. What is meant by “Experiment” in Design of experiment? Four different machines,
M1, M2, M3, and M4, are being considered for the assembling of a particular product. It
is decided that six different operators are to be used in a randomized block experiment
to compare the machines. The machines are assigned in a random order to each
operator. The operation of the machines requires physical dexterity, and it is
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Qp No. 11221518
anticipated that there will be a difference among the operators in the speed with which
they operate the machines. The amounts of time (in seconds) were recorded for
assembling the product: Test the hypothesis, at the 0.05 level of significance, that the
machines perform at the same mean rate of speed.
Operators
Machine 1 2 3 4 5 6
1 42.5 39.3 39.6 39.9 42.9 43.6
2 39.8 40.1 40.5 42.3 42.5 43.1
3 40.2 40.5 41.3 43.4 44.9 45.1
4 41.3 42.2 43.5 44.2 45.9 42.3
/END/
T.B
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