Statistics and Probability — Practice

Question 1

Define the coefficient of variation and state its use.

Accepted Answer

CV = (σ/x̄) × 100%; it compares the consistency of two data sets — the smaller CV is more consistent.

Question 2

Find the range of 8, 3, 11, 6, 14.

Accepted Answer

Range = 14 − 3 = 11.

Question 3

A card is drawn from a pack of 52. Find P(getting a king).

Accepted Answer

Kings = 4; P = 4/52 = 1/13.

Question 4

State the addition theorem of probability.

Accepted Answer

P(A ∪ B) = P(A) + P(B) − P(A ∩ B).

Question 5

If P(A) = 0.3, P(B) = 0.5 and A, B are mutually exclusive, find P(A ∪ B).

Accepted Answer

P(A ∪ B) = 0.3 + 0.5 − 0 = 0.8.

Question 6

If P(A) = 0.6, find P(A′).

Accepted Answer

P(A′) = 1 − 0.6 = 0.4.

Practice — Statistics and Probability