INTERNATIONAL UNIVERSITY OF BUSINESS AGRICULTURE AND TECHNOLOGY Quiz examination STA 240
Set: Z
Full marks: 100
Time: 50 minutes
1. Write down the applications of Poisson distribution and properties of normal distribution. 2. What is random variable? Explain with an example. 3. The number of persons X, in a family chosen at random has the following probability distribution: X P(X)
1 0.1
2 0.2
3 m
4 0.1
5 0.2
A) Find the value of m. B) Find the average family size E (X). C) Also find V(X). 4. p(x)=7x10 ; 1<x<2 A) Find E (X). B) Also find V(X). 5. Hospital records show that of patients suffering from a certain disease, 25% die of it. What is the probability that of 10 randomly selected patients, 5 will recover? 6. A company makes electric motors. The probability an electric motor is defective is 0.05. What is the probability that a sample of 500 electric motors will contain exactly 10 defective motors? 7.
Find the following probabilities: (a) P (Z > 1.06) (b) (c) P (1.01 < Z < 2.04)
Md. Mortuza Ahmmed