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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI 600 034
M.A.DEGREE EXAMINATION ECONOMICS
FIRSTSEMESTER APRIL 2018
EC 1809- MATHS STATISTICS FOR ECONOMISTS
Date: 30-04-2018 Dept. No. Max. 100 Marks
Time: 09:00-12:00
PART A
Answer any FIVE questions in about 75 words each x 4 20)
1. Write a short note on open input-output model.
2. Distinguish between difference equations and differential equations with an example.
3. With the aid of a diagram depict the area of rejection and acceptance in a two-tailed test.
4. Distinguish between perfect positive correlation and perfect negative correlation.
5. 12 coins are tossed at the same time. What is the probability of getting 9 or more heads in a single toss?
6. Find 3A 2B
A [1234] B [−122−1]
7. Find given A =[2540436810]
PART B
Answer any FOUR questions in about 300 words each x 10 40)
8. Solve the following set of simultaneous linear equations using Cramer's rule
5x 6y 4z 15
7x 4y 3z 19
2x y 6z 1
9. Elucidate the procedure for testing hypothesis.
10. Examine the function y x3 -3x2 9x 27 for maximum and minimum values.
11. Find the inverse of [521214056]
12. Explain the properties of Normal distribution.
13. Given Z x2 2xy y2, find the first and second order total differentials.
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14. 1000 students at college level were graded according to their I.Q. and economic conditions. Use χ2 to find out whether there is any association between economic condition and I.Q. (Given for χ2 0.05 3.84)
I.Q.
Economic condition High Low Total
Rich 460 140 600
Poor 240 160 400
Total 700 300 1000
PART C
Answer any TWO questions in about 1200 words each x 20 40)
15. For the following average cost function, find the minimum average cost and show that at minimum average cost, marginal cost and average cost are equal.
25 8x x2
16. A test was given to 5 students chosen at random from M.Com class of each of the three universities in Bihar.
University Scores
A 90 70 60 50 80
B 70 40 50 40 50
C 60 50 60 70 60
Perform ANOVA and show if there is any significant difference between the scores of students in the three universities. (Given F 3.44).
17. Given A [0.10.30.100.20.2000.3] and F [200100], find the output levels.
18. Determine the point which 2inimizes or 2inimizes the function U x2 xy y2 3z2 subject to x 2y 4z 60.