In a Poisson distribution, mean = variance. If the mean is 4, the probability of exactly 2 occurrences is: MCQ with Answer and Explanation

Explanation:
Cost of Living Index measures changes in retail prices of goods and services consumed by households, essentially the Consumer Price Index.

Explanation:
Fisher's ideal index, being the geometric mean of Laspeyres and Paasche indices, is the only common formula that satisfies both time reversal and factor reversal tests, ensuring mathematical consistency.

Explanation:
With two attributes, there are 2² = 4 mutually exclusive classes (AB, Aβ, αB, αβ).