1
Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
MAM SEMESTER 2 • EXAMINATION WINTER 2016
Subject Code: 4120503 Date: 19/11/2016
Subject Name: Business Statistics
Time: 10:30 am to 1:30 pm Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1

Define statistics and explain with illustrations, five uses of statistics in business
07

Calculate average daily wages from the following data:
Daily wage
(in Rs.)
60
80
100
120
160
180
200
No. of persons
5
8
12
22
10
7
6
07
Q.2

State briefly, giving reasons, and the kind of diagram you consider most appropriate for use with each of the following classes of statistical data.
Number of children per family in a large town.
Monthly rainfall for a period of three years.
Monthly output of steel for one year according to the principal grades of quality
07

Compute the S.D. of household size from the following frequency distribution of 500 households covered in a sample survey:
Household size
1
2
3
4
5
6
7
8
9
No. of households
92
49
52
82
102
60
35
24
4
07
OR

The value of median for the following series is determined:
Income(Rs.)
1200
1800
5000
2500
3000
1600
3500
No. of person
12
16
2
10
3
15
7
07
Q.3

Explain the following terms:
Random experiment
Complementary event
Mutually exclusive events
07

If and find P(A U and
07
OR
Q.3

Define a discrete random variable, its mathematical expectation and properties of expected value.
07

There are 2 white and 4 black balls in a box. A person takes 3 balls at random from the box. If he receives Rs. 10 for each white ball and receives Rs. 5 for each black ball, find the expected value of the amount received by him.
07
2
Q.4

Calculate the quartile deviation and its coefficient from the following data:
Class interval
10-15
15-20
20-25
25-30
30-40
40-50
50-60
60-70
frequency
4
12
16
22
10
8
6
4
07

What is correlation? Explain scatter diagram method.
07
OR
Q.4

The sum of squares of difference in ranks for two variables is 33, and the coefficient of rank correlation is 0.8. find the number of pairs of observation.
07

Find the equations of regression lines from the following data and also estimate y for x

3
2

6
4

5
7

5
13
12

2
20
0

07
Q.5

Write a note on: Non Probability Sampling Methods.
07

The average height of a group of soldiers is 68.22" and the variance of height is 10.89. out of 1000 soldiers how many soldiers do you expect to be at least 6 feet tall
07
OR
Q.5

State the properties and uses of normal distribution.
07

The probability distribution of demand of a commodity is given below:
Demand
5
6
7
8
9
10
Probability
0.05
0.1
0.3
0.4
0.1.
0.05
07