Bethune College
(Affiliated to University of Calcutta)
UG Internal Examination (CBCS)
SUBJECT: ECONOMICS, PAPER: CC7, SEMESTER-III, 2022
F.M:10
GROUP-A
(Answer any four questions)
1X4=4
1. The sample mean 𝑥̅ of a simple random sample with replacement is distributed normally
with mean:
𝜎2
𝑛−1
A) 𝜇 and variance 𝑛 (1 − 𝑁−1)
𝜎2
B) 𝜇 and variance 𝑛
𝜎2
𝑛−1
C) 𝜇 and variance𝑛−1 (1 − 𝑁−1)
𝜎2
D) 𝜇 and variance𝑛−1
Where N is the population and n is the sample size.
2. Let X and Y have the joint density function
2𝑥−7𝑦 𝑓𝑜𝑟 0 < 𝑥, 𝑦 < ∞
𝑓(𝑥, 𝑦) = {𝑒
𝑂𝑡ℎ𝑒𝑟𝑤𝑖𝑠𝑒
0
A) X and Y stochastically independent
B) X and Y stochastically dependent
C) None of the above
3. The sample mean is a better estimator than the sample median in all respect
A) True
B) False
C) Inconclusive
D) None of the above
4. In case of a normal distribution,
A) Mean> Median> Mode
B) Mean< Median< Mode
C) Mean= Median= Mode
D) None of the above
5. For any distribution, state which of the following statement is true:
A) The median is greater than the 7th Decile
B) The 3rd Quartile is equal to the 55th Percentile
C) The 2nd Quartile is equal to the 5th Decile
D) None of the above
Internal Examination, Semester: I/ II/ III/ IV/ V/ VI, Date:
GROUP-B
(Answer any two questions)
3X2=6
1. What is the difference between probability mass function and probability density
function?
2. The median and mode of the following wage distribution are known to be Rs. 3,350
an Rs. 3,400 respectively. Find the values of f1, f2 and f3
0-1000
1000-2000
2000-3000
3000-4000
4000-5000
5000-6000
6000-7000
Total
4
16
f1
f2
f3
6
4
230
3. Suppose a box contains 10 blue balls and 10 red balls. Four balls are drawn at random
from the box. Let X be the number of blue balls drawn and Y be the number of red
balls drawn. Draw the regression line of X on Y.
Internal Examination, Semester: I/ II/ III/ IV/ V/ VI, Date: