2021 Jan

Question 6

The life in days, X, of an insect is such that log₁0 X is normally distributed with mean of

2 days and standard deviation of 0.2 days.

(a) Calculate the probability that an insect will have a life of

(i) more than 200 days;

(b) between 50 and 150 days inclusive.

Two insects have life expectancies of 7₁ and 72, and H= T₂

(i) Show and describe the distribution type of logio H, if their life

expectancies are independent.

If one insect has life expectancy 1.8 times that of the other, is this

difference significant?