Full Text Transcript
Text below was recognized via OCR from scanned pages and may contain minor errors. Mathematical formulas and symbols may be approximate - please refer to the PDF for the exact equations.
Time Allowed : Three Hours
INDIAN FOREST SERVICE (MAINJEXAM- 2023
STATISTICS
Paper - II
BJKE-B-STSC
Maximum Marks : 200
Question Paper Specific Instructions
Please read each of the following instructions carefully before attempting
questions :
There are EIGHT questions in all, out of which FIVE are to be attempted.
Questions no. 1 and 5 are compulsory. Out of the remaining SIX questions, THREE are
to be attempted selecting at least ONE question from each of the two Sections A and B.
Attempts of questions shall be counted in sequential order. Unless struck off, attempt of a
question shall be counted even if attempted partly. Any page or portion of the page left
blank in the Question-cum-Answer Booklet must be clearly struck off.
All questions carry equal marks. The number of marks carried by a question/part is
indicated against it.
Unless otherwise mentioned, symbols and notations have their usual standard meanings.
Assume suitable data, if necessary and indicate the same clearly.
Answers must be written in ENGLISH only.
BJKE-B-STSC
Ql. (a)
(b)
(c)
(d)
(e)
BJRE-B-STSC
SECTION A
Derive a control chart to test p = 400 given that o = 30 such that the
chances of a point going out of the control limits when the process really
is in control are 1 in 20 while the chances of detecting a shift of to 425
within two samples after a shift occurs are 0-99 percent. For the same
chart, what are the chances of detecting a shift of u from 400 to 380
within two samples ?
Define renewal process. Derive the renewal function.
Represent a general linear programming problem consisting of n
variables and m constraints, in its canonical and standard forms. Given
the following linear programming problem :
Maximize z = x; + 1-5x,
subject to the constraints
2x, + 2x5 < 160
xX, + 2x. < 120
4x, + 2x. < 280
Xj, X2 20
find the solution of the problem using graphical method.
Define the pay-off matrix in a two-person zero-sum rectangular game.
Obtain a necessary and sufficient condition under which the game
possesses a saddle point.
A study about a population showed that the mobility of the population of
a state to a village, town and city is in the following percentages :
To
From
Village Town City
Village 60 25 15
Town 10 70 20
City 10 30 60
What will be the proportion of population in the village, town and city
after one year and two years, given that the present population has
proportions of 0-50, 0-40 and 0-10 in the village, town and city
respectively ?
Standard Normal Probabilities
PIZ < 2]
2 00 01 02 03 „04 ‘05 ‘06 07 08 09
0.0 -5000 .5040 .5080 -5120 -5160 -5199 239 -5279 -5319 -5359
0.1 .5398 .5438 .5478 5517 ಪಚ್ 5596 5636 .5675 714 753
0.2 793 5832. 871 5910 5948 .5987 6026 -6064 -6103 6141
0.3 -6179 6217 .6255 -6293 -6331 .6368 -6406 6443 -6480 -6517
0.4 .6554 -6591 .6628 -6664 -6700 -6736 .6772 -6808 -6844 -6879
0.5 .6915 -6950 .6985 .7019 .7054 -7088 #123 ‘7157 ‘7190 7224
0.6 ‘7257 7291 7324 ‘7357 .7389 .7422 .7454 -7486 క .7549
0.7 -7580 1 2 .7673 .7704 .7734 .7764 .7794 -7823 -7852
0.8 7881 0 .7939 .7967 .7995 .8023 .8051 -8078 .8106 .8133
0.9 -8159 .8186 .8212 .8238 .8264 -8289 -8315 -8340 .8365 -8389
1.0 8413 8438 -8461 8485 8508 8531 8554 8577 .8599 .8621
বড 8643 8665 .8686 -8708 „8729 .8749 .8770 -8790 .8810 .8830
1.2 8849 8869 :8888 8907 8925 .8944 ৪962 .8980 8997 -9015
1.3 -9032 -9049 -9066 -9082 -9099 .9115 -9131 -9147 -9162 -9177
1.4 -9192 -9207 -9222 .9236 .9251 -9265 -9279 -9292 -9306 -9319
ES -9332 .9345 9357 9370 9382 9394 .9406 9418 9429 ೬9441
1.6 9452 9463 9474 9484 9495 9505 9515 9525 -9535 -9545
1.7 -9554 ೨564 9573 -9582 -9591 9599 -9608 -9616 -9625 -9633
1.8 -9641 -9649 -9656 -9664 -9671 -9678 -9686 -9693 -9699 -9706
1.9 -9713 .9719 -9726 -9732 -9738 9744 -9750 -9756 -9761 -9767
2.0 2 .9778 .9783 -9788 -9793 -9798 -9803 -9808 -9812 -9817
2:1 -9821 -9826 -9830 .9834 .9838 -9842 -9846 -9850 -9854 -9857
2.2 -9861 -9864 -9868 9871 9875 9878 .9881 -9884 -9887 -9890
23 -9893 -9896 -9898 -9901 -9904 -9906 .9909 .9911 -9913 -9916
2.4 9918 9920 9922 9925 -9927 -9929 -9931 -9932 -9934 -9936
25 -9938 -9940 .9941 -9943 -9945 -9946 -9948 .9949 .9951 9952
2.6 9953 .9955 .9956 .9957 -9959 9960 9961 9962 -9963 -9964
2.7 -9965 -9966 -9967 -9968 -9969 .9970 .9971 -9972 -9973 -9974
2.8 -9974 9975 9976 9977 9977 -9978 9979 ೨979 -9980 .9981
2.9 -9981 -9982 -9982 .9983 -9984 ೨984 9985 -9985 ೬೨೨986 ೨೨86
3.0 ೨9987 -9987 -9987 -9988 -9988 -9989 -9989 -9989 -9990 -9990
3:1 -9990 -9991 -9991 .9991 .9992 -9992 -9992 -9992 -9993 -9993
me -9993 -9993 -9994 -9994 -9994 -9994 -9994 -9995 -9995 -9995
33 -9995 -9995 -9995 -9996 -9996 -9996 -9996 -9996 -9996 -9997
3.4 .9997 .9997 9997 9997 .9997 -9997 -9997 -9997 -9997 -9998
3.5 -9998 -9998 -9998 -9998 -9998 -9998 -9998 -9998 -9998 .9998
BJKE-B-STSC 3
Q2. (a)
(b)
(c)
Q3. (a)
BJKE-B-STSC
Find a sequential plan for which, in the usual notation p, = 0-01,
a = 0:05, py = 0-06 and f = 0-10. Display the plan in a table for the first
46 units.
@ A system is composed of five identical independent elements in
parallel. What should be the reliability of each element to achieve
a system reliability of 0-96 ?
(ii) Three identical units each with a reliability of 0-9 for a system are
operating in parallel. What is the system reliability if at least one
of the units is required for the system to be successful ? If you add
another unit with identical reliability characteristics, what will
be the increase in system reliability ?
Consider a system where m — 1 units are standing by to support one
basic unit. Obtain the system reliability assuming the units are
identical. Show that for a two unit system the reliability of a standby
system is better than that of an active redundant system.
What is the basic philosophy behind sensitivity analysis ? What are the
issues which could be answered using sensitivity analysis in linear
programming problems ?
For the following linear programming problem :
Maximize z= 3x, + 2x»
subject to the constraints
X1 + 2X5 <6
2x, +X_ <8
—X,+X_ <1
X_ <2
Xy, X_g20
the optimal simplex table is obtained as
3..2°°0 0. 02:0
i | Basis | Cost | Solution
By, XQ%2 By 4 8o° Bane
1] xX, 2 4/3 0 1 2% -1/3 0 O
2: 3 10/3 T 0°13" 228.020
3] 83 0 3 0 0 -1 Beier bg)
4 S4 0 2/3 0 083228 SIR Oat
z 38/3 O° 20° 132 AB 0 20
where s; (i = 1, 2, 3, 4) denotes the slack variable used in the
ith constraint.
15
10
(b)
(c)
BJKE-B-STSC
(i) Find the status and worth of each resource.
(ii) | Find the possible range of the cost coefficient associated with the
variable x, for which the optimum solution remains unchanged. 15
Explain what is a Transportation Problem (TP). Differentiate between
balanced and unbalanced transportation problems.
Four petrol dealers A, B, C, D require 50,000, 40,000, 60,000 and
40,000 litres of petrol respectively. It is possible to supply these
demands from three locations 1, 2 and 3 which have 80,000, 1,00,000
and 50,000 litres respectively. The costs (in rupees per thousand litres)
to ship the petrol from different locations to different dealers are shown
in the following table :
Dealer
Location Supply
A B Cc D
1 70 60 60 60 8
2 50 80 60 70 10
3 80 50 80 60 5
Required 5 4 6 4
(The supply and requirement values in the table have been multiplied
by 10-4 to make computations easier)
Determine the amount of petrol to be shipped from each location to each
dealer so that all the dealers’ requirements are satisfied and the total
shipping costs are a minimum. 15
Prove that if the pair of linear programming problems
Maximize Z = C'X
subject to
AX <b
X 20
and
Minimize Z* = b'Y
subject to
A'Y =C
Y=0
have feasible vectors X and Y, then they have optimal vectors such that
Maximum C’X = Minimum b’Y. 10
Q4. (a)
(b)
(c)
BJKE-B-STSC
Construct a V-mask for the following data with » = 10 and o = 1 and
comment. (Given a = 0:0027, B = 0-01, 5=1)
Period x. Period x. Period _
. i . i ; i
i i i
1 9-45 11 9-03 21 10-90
2 7-99 12 11:47 22 9-33
3 9-29 13 10°51 23 12:29
4 11-66 14 9-40 24 11:50
5 12-16 15 10-08 25 10-60
6 10-18 16 9:37 26 11-08
7 8-04 17 10-62 27 10:38
8 11-46 18 10°31 28 11-62
9 9-20 19 8-52 29 11:31
10 10-34 20 10-84 30 10°52
Distinguish between deterministic and probabilistic inventory problems.
Discuss the continuous case of a probabilistic inventory model with
instantaneous demand and no set-up cost.
A sweet company sells chocolate-based sweets by the kilogram (kg). On
every kg of these sweets sold on the day of its preparation, the company
makes a profit of = 0-55 per kg. The company disposes of all the
chocolate-based sweets not sold on the date of its preparation, at a loss
of € 0-22 per kg. If the demand is known to be rectangular between
2000 and 4000 kg, determine the optimum daily amount of sweets
prepared.
Obtain the steady-state solution for P,, the probability of n customers at
any arbitrary point of time in the (M/M/C) : (oo/FIFO) queue system.
Hence, find the formulae for (i) Traffic intensity, (ii) The probability that
an arriving customer has to wait, and (iii) The average number of
customers in the queue.
15
10
15
SECTION B
Q5. (a) What is an index number ? Describe the general lines on which you
proceed to construct a cost of living index for factory workers in an
industrial area. 8
(b) Explain seemingly unrelated regression model. Obtain the generalized
least squares estimator of the parameter vector when the covariance
matrix is diagonal. 8
(c) Explain the two series of acreage statistics available in India. 8
(d) What are the defects in comparing mortality situations between two
regions by means of their crude death rates ? Explain how these defects
can be eliminated. 8
(e) Describe different methods of converting raw scores into some
equivalent comparable scores in Psychometry. 8
Q6. (a) (i) Obtain the autocorrelation function of AR(2) process and show
that the process is covariance stationary. 8
Gi) Obtain the best forecast in the mean square sense for
ARIMA (p, d, q) process. 7
(b) For a model :
Yyt = Byo Yo + M11 Xe + Yat
Yor = Boi Vit + Yoo Xot + Yo3 Xat + Use
1 O 0 5 610
XX=|0 20 0] and XY=|40 20
0 oO 10 20 30
Determine the identifiability of each equation and estimate the
parameters by using an appropriate method. 15
(c) | Explain the existing machinery for collection of births and deaths in
India and its shortcomings. 10
BJKE-B-STSC 7
Q7. (a)
(b)
(c)
Q8. (a)
(b)
BJKE-B-STSC
Describe the major sources of demographic data in India. 15
Calculate (i) General Fertility Rate (ii) Total Fertility Rate, and
(iii) Gross Reproduction Rate from the following data.
Age group of females | No. of females (000) | Total Births
15-19 16-0 260
20 — 24 16-4 2244
25 — 29 15:8 1894
30 — 34 15-2 1320
35 — 39 14:8 916
40 — 44 15-0 280
45 — 49 14-5 145
Assume that the proportion of female births is 46-2 percent. 15
Explain the concept of validity of a test. Discuss the different types of
validity. 10
Compute Laspeyres’ quantity and price index numbers for 2005.
: 1995 2005
Commodity : .
Quantity Value Quantity Value
A 50 350 60 420
B 120 600 140 700
Cc 30 330 20 200
D 20 360 15 300
E 5 40 5 50
Also show that Fisher’s ideal index number satisfies factor reversal test. 15
The model appropriate for the following data is given by
Y; =at BX, + u; where v(u;) = x, pee Donne m. Obtain the
generalized least square estimates and their variances. 15
marcas, 6. le 1011
X,: 23 4 5 6
Ae ee Gee a a
(c)
BJKE-B-STSC
A part of a life table is given with most of the entries missing. On the
basis of the available figures, complete the missing ones.
Age
x l, dy dx L, Ty
87 34 — | 0:2353 - -
88 - — | 0-2308 ~ -
89 - — | 0-2500 ~ -
90 - — | 0:2667 — | 35-5
9
10

