**981. Var (X) = ?**

A. E[X2]

B. E[X2] – E[X]

C. E[X2] + E[X]2**D. E[X2] – E[X]2**

**982. Var (X + Y) = ?**

A. E[X/Y] + E[Y]

B. E[Y/X] + E[X]**C. Var(X) + Var(Y) + 2 Cov(X, Y)**

D.Var(X) + Var(Y) – 2 Cov(X, Y)

**983. What is variance of the data set: 2, 10, 1, 9, and 3?**

A. 15.5**B. 17.5**

C. 5.5

D. 7.5

**984. In a module, quiz contributes 10%, assignment 30%, and final exam contributes 60% towards the final result. A student obtained 80% marks in quiz, 65% in assignment, and 75% in the final exam. What are average marks?**

A. 64.5%

B. 68.5%**C. 72.5%**

D. 76.5%

**985. What is the average of 3%, 7%, 10%, and 16% ?**

A. 8%**B. 9%**

C. 10%

D. 11%

**986. If an experiment is repeated independently for a large number of times, it converges to a/an****A. expected value**

B. variance – mean

C. normal distribution

D. uniform distribution

**987. Which statistical method is used to estimate the relationship between two variables?**

A. Correlation**B. Regression**

C. Covariance

D. ANOVA

**988. The value of R2, the coefficient of determination, is always between****A. 0 and 1, including 0 and 1**

B. 0 and 1, excluding 0 and 1

C. –1 and 1, including –1 and 1

D. –1 and 1, excluding –1 and 1

**989. The mean, mode, and median of the data set: 5, 4, 10, 12, 1, 5, 3, 7, 15, and 8 is respectively**

A. 5, 6, 7

B. 7, 6, 5

C. 6, 5, 7**D. 7, 5, 6**

**990. “Rolling of a die” is an example of a random**

A. event

B. outcome**C. experiment**

D. sample space