7. Of a population of Caribbean country, 25% have blood type . In a random sample of 150 people, find approximate values for the probabilities that:

(i) 20 or fewer of blood group .

(ii) 30 or more are of blood group .

8. 2% of all births in country A are twins. If there are 500 births in one week, calculate the following:

(i) The probability that more than 10 births in one week would result in twins

(ii) The probability that at least 5 births in a week results in a week.

9. The random variable has a uniform distribution over the interval (-1, 2).

(i) What is the pdf of this random variable?

(ii) Compute the probability that is greater than 0

(iii) Calculate (1 < < 2).

10. The duration in minutes, of a telephone call made by a certain lady to her friend is continuous random variable having a probability density function (), where () = 5, > 0

(i) Find the value of

(ii) Calculate the probability that a call by this lady will last for more than 10 minutes.

(iii) Calculate the probability that a call by this lady will last for less than 5 minutes.