LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – STATISTICS
THIRD SEMESTER – APRIL 2008
ST 3501 / 3500 - STATISTICAL MATHEMATICS - II
Date : 26/04/2008
Time : 1:00 - 4:00
Dept. No.
NO 12
Max. : 100 Marks
SECTION - A
Answer ALL the Questions
(10 x 2 = 20 marks)
1. Define Upper and Lower Sums of a function corresponding to a given partition of a closed
interval.
2. State the Second Mean Value theorem for integrals.
3. If f(x) = C x2 (1 – x), for 0 < x < 1 is a probability density function (p.d.f.), find the value of C.
4. Define improper integral of second kind.

1
5. Show that the improper integral  x
dx converges (where a > 0)
a e 1
 2 
6. Find L–1  ( s  a) 3 


7. State the general solution for the linear differential equation
dy
+ Py = Q
dx
8. State the postulates of a Poisson Process.
9. State the Fundamental Theorem on a necessary and sufficient condition for the consistency of a
system of equations A x + b = 0 .
~
~
~
10. If λ is a characteristic root of A, show that λ2 is a characteristic root of A2.
SECTION - B
Answer any FIVE Questions
(5 x 8 = 40 marks)
11. Let Pn = {0, 1/n, 2/n, ….., (n – 1)/n, 1} be a partition of [0, 1]. For the function f(x) = x, 0 ≤x ≤
1, find lim U[Pn, f] and lim L[Pn, f]. Comment on the integrability of the function.
n 
n 
1
12. Evaluate: (i) 
x
0 1 x
 /4
d x (ii)
4
x dx
0

13. Show that the integral
 Sin
1
x
p
dx (where a > 0) converges for p > 1 and diverges for p ≤ 1.
a
14. Define Beta integrals of First kind and Second kind. Show that one can be obtained from the
other by a suitable transformation.
(P.T.O)
2
3
dy
3x y  y
15. Solve:
=
dx
3 y 2 x  x3
16. Solve: (D2 + 4D + 6) y = 5 e– 2 x
1
17. Establish the relationship between the characteristic roots and the trace and determinant of a
matrix.
18. Give a parametric form of solution to the following system of equations:
4x1 – x2 + 6x3 = 0
2x1 + 7x2 +12x3 = 0
x1 – 4x2 – 3x3 = 0
5x1 – 5x2 +3x3 = 0
SECTION - C
Answer any TWO Questions
(2 x 20 = 40 marks)
19. (a) State and prove the First Fundamental Theorem of Integral Calculus.
2
1
5x2
x4
(b) Evaluate (i)  2
dx (ii)  2 dx
0 x 4
0 x 1
(12+8)
20. (a) Show that mean does not exist for the distribution with p.d.f.
1 1
f(x) =
,–∞<x<∞
 1 x 2
d
(b)L[f(t)] = F(s), show that L[t f(t)] = –
F(s). Using this result find L[t2 e– 3 t]
ds
(8+12)
21. Evaluate: (a) ∫ ∫ x2 y2 dx dy over the circle x2 + y2 ≤ 1.
(b) ∫ ∫ y dx dy over the region between the parabola y = x2 and the line x + y = 2
(10+10)
22. (a) State and Prove Cayley-Hamilton Theorem.
(b) If P is a non-singular matrix and A is any square matrix, show that A and
P–1AP have the
same characteristic equation. Also, show that if ‘x’ is a characteristic vector of A, then P–1 x is a
characteristic vector of P–1AP.
(12+8)
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