SSC CGL JSO Statistics Paper, Most Important Questions & Topic Wise-Weightage

Q1) If the mean of 5 numbers is 12 and one number is replaced by 20, the new mean becomes 14. Find the number replaced.

Q2) For a continuous random variable X with pdf f(x) = kx² for 0 ≤ x ≤ 2, find k.

Q3) The coefficient of skewness (Karl Pearson) for a distribution with mean = 50, median = 47, and standard deviation = 4 is:

Q4) If two variables X and Y have a correlation coefficient of 0.8, then the coefficient of determination is:

Q5) If the variance of X is 16, what is the variance of 3X + 5?

Q6) The Spearman’s rank correlation coefficient between two variables with tied ranks can be calculated using:

Q7) In a two-way ANOVA with r = 3 rows and c = 4 columns, the degrees of freedom for interaction is:

Q8) A sample of 100 observations has a mean of 50 and SD of 10. The standard error of the mean is:

Q9) For a binomial distribution with n = 10 and p = 0.5, variance is:

Q10) If the probability of A = 0.4, probability of B = 0.5, and P(A ∩ B) = 0.2, then P(A | B) = ?

Q11) For a binomial distribution with n = 10 and p = 0.5, variance is:

Q12) The probability generating function (PGF) of a Poisson variable with mean λ is:

Q13) If Q1 = 20, Q3 = 40, and median = 30, then Bowley’s coefficient of skewness is:

Q14) In regression analysis, the sum of residuals is:

Q15) For a normal distribution N(μ, σ²), the probability that X lies within μ ± 2σ is approximately:

Q16) For a sample of size n from a population, the unbiased estimator of population variance is:

Q17) In a Poisson distribution, the probability of exactly 2 events is 0.224. If the mean is 2, what is P(X = 2)?

Q18) If a time series has seasonal variation, it can be removed by:

Q19) If population size N = 1000 and sample size n = 100, the sampling fraction is:

Q20) The Chi-square test is used for: