Issue 1

A survey in Estrie on 3400 patients reveals that 87% of individuals were carriers of a mysterious virus (!). If, the next day, public health tests 7 individuals:

(a) What is the probability distribution of the number of infected individuals? (b) What is the probability of having no infected individuals? (c) What is the probability of having only infected individuals? (d) What is the probability of having at least two infected individuals? (e) What is the probability of having less than four infected individuals? (f) What is the expected number of infected individuals in a sample of seven? (g) What is the variance in the distribution of the number of infected individuals? (h) What is the skewness coefficient of the probability distribution?

Issue 2

In 1971, in France, 168,385 employees had an accident, out of a total employee population of 12

805,055 employees. Assuming the probability of having an accident is the same for everyone:

(a) What is the probability of no accidents in a village with 1445 wage earners? (b) What is the probability of fewer than 20 accidents in this village? (c) What is the probability that more than 25 employees have an accident?

Issue 3

1) Find the following probabilities by looking at the table of :

(a) P (₍₂₅₎ > 40.65) (b) P (₍₆₎ 12.59)

2) Find the values of that correspond to the following expressions: (c) P ( ₍₄₀₎ > _(:40)) = 0.75

(d) P (_{(90) (:90)}) = 0.995