ExamBharo · SSC CGL 2024 Tier II — Statistics — 19 January 2025 · exambharo.com/previous-year-papers/ssc-cgl-2024-tier-2-statistics-19-jan/
Question paper · SSC CGL
SSC CGL 2024 Tier II — Statistics — 19 January 2025
19 January 2025 · 9:00 AM–11:00 AM81 of the paper’s 100 questions1 per correct answer
19 questions of the original paper are not included: those that need a figure or formatting we cannot show, that have no answer in the response sheet, or that we could not check against a second copy of the paper.
Questions from the Staff Selection Commission’s paper of 19 January 2025, 9:00 AM–11:00 AM. Each question’s answer is under it, hidden until you open it, and the full answer key is at the end. Take the paper as a timed practice test to be scored.
Statistics
1.

- (a)

- (b)

- (c)

- (d)

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Answer: (d)
- (a)
2. Monthly sales data (in units) shows the following trend-adjusted ratios for three months: January (1.1), February (0.9), and March (1.0). What is the average seasonal index for this quarter?
- (a) 0.95
- (b) 0.9
- (c) 1.0
- (d) 1.1
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Answer: (c)
3. Duncan’s Multiple Range Test makes use of which statistical measure?
- (a) Standard Error of the Means
- (b) Regression Coefficient
- (c) Range Statistic (R)
- (d) F-statistic
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Answer: (c)
4.

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- (b)

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Answer: (c)
- (a)
6. If the critical region is evenly distributed, then the test is referred to as:
- (a) Three tailed
- (b) Zero tailed
- (c) One tailed
- (d) Two tailed
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Answer: (d)
7.

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Answer: (c)
- (a)
8. In a two-way ANOVA, how many hypotheses are tested?
- (a) Three
- (b) One
- (c) Four
- (d) Two
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Answer: (a)
9. In ANCOVA, what happens when the covariate is not linearly related to the dependent variable?
- (a) The results of ANCOVA may be biased.
- (b) The covariate becomes irrelevant.
- (c) All assumptions of ANCOVA are met.
- (d) The F-statistic becomes insignificant.
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Answer: (a)
10. Let X and Y be two independent Poisson variates with rate 5 and 10, respectively, then the E(XY=2) is equal to:
- (a)

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Answer: (b)
- (a)
11.

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Answer: (b)
- (a)
12.

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Answer: (c)
- (a)
13.

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Answer: (d)
- (a)
14.

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Answer: (a)
- (a)
15.

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Answer: (b)
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17.

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Answer: (c)
- (a)
18.

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Answer: (a)
- (a)
20.

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Answer: (b)
- (a)
22.

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Answer: (c)
- (a)
23. For testing whether two independent Normal populations (with unknown and equal variances) have same mean, one uses:
- (a) t distribution
- (b) Standard Normal Distribution
- (c) Chi Square Distribution
- (d) F distribution
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Answer: (a)
24. The following data represents a time series. Period : 1 2 3 4 5 Observed values : 150 140 160 170 180 Compute the first-order and second-order differences for period 3.
- (a) First-Order: 20, Second-Order: −30
- (b) First-Order: −10, Second-Order: −10
- (c) First-Order: −10, Second-Order: 20
- (d) First-Order: 20, Second-Order: 10
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Answer: (a)
26.

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Answer: (c)
- (a)
27. A model being fitted is said to be adequate if the residual plot:
- (a) is quadratic
- (b) is non-linear
- (c) is U-shaped
- (d) displays random pattern
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Answer: (d)
28.

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Answer: (b)
- (a)
29.

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Answer: (c)
- (a)
30.

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Answer: (a)
- (a)
32.

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Answer: (c)
- (a)
33.

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Answer: (c)
- (a)
34. Level of significance is:
- (a) Probability of Type I Error
- (b) 1 − Probability of Type I Error
- (c) 1 − Probability of Type II Error
- (d) Probability of Type II Error
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Answer: (a)
35.

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Answer: (b)
- (a)
36.

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Answer: (d)
- (a)
37.

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Answer: (b)
- (a)
38. Before using secondary data, one need NOT verify:
- (a) reliability of data
- (b) suitability of data
- (c) expenditure involved at time of collection of data
- (d) adequacy of data
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Answer: (c)
39.

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Answer: (b)
- (a)
41.

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Answer: (a)
- (a)
42.

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Answer: (c)
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43.

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Answer: (d)
- (a)
44.

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Answer: (c)
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45.

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Answer: (c)
- (a)
46.

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Answer: (a)
- (a)
47. O-gives are NOT useful for locating:
- (a) percentiles
- (b) median
- (c) quartiles
- (d) mean
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Answer: (d)
48.

- (a)

- (b)

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Answer: (c)
- (a)
49. Which component of a time series represents short-term fluctuations due to seasonal factors?
- (a) Seasonal component
- (b) Irregular component
- (c) Cyclical component
- (d) Trend
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Answer: (a)
50.

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- (b)

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Answer: (b)
- (a)
51. Which of the following statements is FALSE?
- (a) An alternative hypothesis is complementary to null hypothesis.
- (b) The hypothesis for testing mu < mu0 is two sided / two tailed.
- (c) The null hypothesis H0: mu = mu0 can be tested against the alternative H1: mu not equal to mu0.
- (d) The hypothesis for testing mu > mu0 is one sided / right tailed.
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Answer: (b)
52.

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Answer: (d)
- (a)
53.

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Answer: (a)
- (a)
54.

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Answer: (c)
- (a)
55. If S2 is the sample variance of a sample of size n and s2 is an unbiased estimator of population variance, then which of the following is true?
- (a)

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Answer: (b)
- (a)
56.

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Answer: (a)
- (a)
58.

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Answer: (a)
- (a)
59.

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Answer: (b)
- (a)
60. It has been found that 2% of the tools produced by a certain machine are defective. What is the probability that in a shipment of 400 such tools, 3% or more will be defective? (Probability that the normal variate lies between 0 and 1.43 is 0.4236.)
- (a) 0.0764
- (b) 0.50
- (c) 0.4236
- (d) 1.43
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Answer: (a)
62.

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Answer: (a)
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63.

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Answer: (b)
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64.

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Answer: (b)
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65.

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Answer: (a)
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66.

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Answer: (d)
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67.

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Answer: (c)
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68.

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Answer: (d)
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69.

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Answer: (b)
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70.

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Answer: (a)
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74.

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Answer: (d)
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75.

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Answer: (d)
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76.

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Answer: (b)
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77.

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Answer: (c)
- (a)
78. If (X, Y) has a bivariate normal distribution, then X, Y are independent if and only if X, Y are:
- (a)

- (b)

- (c)

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Answer: (b)
- (a)
80. Let X1 , X2 , . . . , X10 be 10 independent and identically distributed (i.i.d) random variables taking the values 0, 1 with corresponding probabilities q, p. Then X = X1 + X2+ . . . + X10 is/has:
- (a) a binomial variate
- (b) Poisson distribution
- (c) a normal variate
- (d) a geometric variate
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Answer: (a)
82.

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Answer: (b)
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83.

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Answer: (d)
- (a)
84. Which of the following is NOT true about collecting data through structured interviews?
- (a) They involve the use of highly standardised techniques of recording.
- (b) The interviewer follows a rigid laid down procedure.
- (c) They involve the use of a set of predetermined questions.
- (d) The sequence of asked questions can be changed.
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Answer: (d)
85.

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Answer: (d)
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86.

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Answer: (c)
- (a)
88. In a one-way ANOVA, which of the following would indicate a violation of the normality assumption?
- (a) Equal variances across groups
- (b) Residuals showing a skewed distribution
- (c) Residuals randomly distributed
- (d) Independent observations
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Answer: (b)
89. What is the main assumption of the ratio-to-moving-averages method?
- (a) Seasonal effects are multiplicative.
- (b) Random components dominate the time series.
- (c) The trend is constant over time.
- (d) The seasonal component is additive.
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Answer: (d)
92.

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Answer: (d)
- (a)
93. From a population of a large number of workers with a standard deviation 5, a sample is drawn and the standard error is found to be 0.5. What is the sample size?
- (a) 50
- (b) 1000
- (c) 10
- (d) 100
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Answer: (d)
94.

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Answer: (b)
- (a)
95.

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Answer: (d)
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97.

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Answer: (d)
- (a)
99.

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Answer: (a)
- (a)
100.

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Answer: (c)
- (a)
Show answers
Answer key
Answer key as marked in the Staff Selection Commission’s response sheet. “—” means the sheet did not show it clearly.
Statistics
- Q 1
- (d)
- Q 2
- (c)
- Q 3
- (c)
- Q 4
- (c)
- Q 6
- (d)
- Q 7
- (c)
- Q 8
- (a)
- Q 9
- (a)
- Q 10
- (b)
- Q 11
- (b)
- Q 12
- (c)
- Q 13
- (d)
- Q 14
- (a)
- Q 15
- (b)
- Q 17
- (c)
- Q 18
- (a)
- Q 20
- (b)
- Q 22
- (c)
- Q 23
- (a)
- Q 24
- (a)
- Q 26
- (c)
- Q 27
- (d)
- Q 28
- (b)
- Q 29
- (c)
- Q 30
- (a)
- Q 32
- (c)
- Q 33
- (c)
- Q 34
- (a)
- Q 35
- (b)
- Q 36
- (d)
- Q 37
- (b)
- Q 38
- (c)
- Q 39
- (b)
- Q 41
- (a)
- Q 42
- (c)
- Q 43
- (d)
- Q 44
- (c)
- Q 45
- (c)
- Q 46
- (a)
- Q 47
- (d)
- Q 48
- (c)
- Q 49
- (a)
- Q 50
- (b)
- Q 51
- (b)
- Q 52
- (d)
- Q 53
- (a)
- Q 54
- (c)
- Q 55
- (b)
- Q 56
- (a)
- Q 58
- (a)
- Q 59
- (b)
- Q 60
- (a)
- Q 62
- (a)
- Q 63
- (b)
- Q 64
- (b)
- Q 65
- (a)
- Q 66
- (d)
- Q 67
- (c)
- Q 68
- (d)
- Q 69
- (b)
- Q 70
- (a)
- Q 74
- (d)
- Q 75
- (d)
- Q 76
- (b)
- Q 77
- (c)
- Q 78
- (b)
- Q 80
- (a)
- Q 82
- (b)
- Q 83
- (d)
- Q 84
- (d)
- Q 85
- (d)
- Q 86
- (c)
- Q 88
- (b)
- Q 89
- (d)
- Q 92
- (d)
- Q 93
- (d)
- Q 94
- (b)
- Q 95
- (d)
- Q 97
- (d)
- Q 99
- (a)
- Q 100
- (c)