|STAT 13 (1a, 1b, 1c)
Introduction to Statistical Methods for the Life and Health Science
|Department of Statistics
Instructor: Ivo Dinov
|Due Date: Friday, Feb. 06, 2004
(HW_3_1) A manufacturer of disk drives for a well-known brand of computers expects 3% of the drives to malfunction during the computers warranty period. Let X be the number of disk drives, in a batch of 11 randomly selected disk drives, which malfunction during this period. X has a Binomial distribution.
- Identify n and p, the parameters of the Binomial random variable.
- In the context of this exercise, state the assumptions required for X to have a Binomial distribution.
- Are the Binomial assumptions satisfied here?
- Calculate the probability that:
- No disk drive will malfunction during the warranty period.
- Exactly one disk drive will malfunction during the warranty period.
- At least two disk drives will malfunction during the warranty period.
- Between 2 and 5 (inclusive) disk drives will malfunction during the warranty period.
(HW_3_2) Assume the distribution of human blood types in one geographic
region is: 25% type A; 15% type B; 49% type O and; 11% type AB. Suppose we
select one married couple at random, with the husband and the wife following
this blood type distribution.
- If the wife has type B blood, what is the probability that the husband has blood type B?
- What is the probability that both husband and wife have type A blood?
- What is the probability that at least one of them has blood type AB?
- What is the probability that they have the same blood type?
(HW_3_3) Members of a health club are classified by gender and number of days per week they exercise. Days per week spent exercising
|Gender \ Days of Exercise||A(0-1)||B(2-3)||C(4-5)||D(6-7)|
What is the probability that a randomly selected health club member:
- is a female?
- is a female and exercises 2-5 times a week?
- is a male or exercises 4 or more times a week?
- is a male given that the person exercises less than 3 times a week?
Last modified on