Probability & Statistics problems

Assignment - 1, MATH 312, Semester 391, JUC -Female Branch Page 1 of 3

Jubail University College

Probability & Statistics

Assignment - I

Due Date: 14 /10/2018

Name: __________________________________ ID: ____________________ Section: ______

I. Suppose a car Dealership has tracked the number of used cars sold at its downtown dealership. Consider the following data representing the population of cars sold in each of 10 weeks that dealership has been

open.

3, 6, 9, 8, 4, 7, 8, 2, 0, 5

A. Find the sample mean and median.

B. Find the Mode.

C. Find the sample variance and standard deviation.

D. Find 25th quartile range.

Assignment - 1, MATH 312, Semester 391, JUC -Female Branch Page 2 of 3

II. Of 500 employees, 225 participating in a company’s profit sharing plan, 250 having major medical insurance coverage and 25 participating in both programs. Find the probability that a random selected employee

A. will be a participant in at least one of the two programs.

B. will not be a participant in either programs.

C. will be a participant in exactly one program.

III. Two events occurs with probabilities ( | ) 0.4, ( ) 0.2 ( | ) 0.5P A B = P A B , and P B A .   Compute

A. Compute ( )P A B .

B. Compute ( )P B .

C. Are event A and B independent events? Why?

D. Are event A and B mutually exclusive events? Why?

Assignment - 1, MATH 312, Semester 391, JUC -Female Branch Page 3 of 3

IV. Suppose a quality manager for hp computers has collected following data on the quality status of disk drives by supplier. She inspect a total of 600 disk drives as shown below.

Supplier Drive status Total

Working Defective

Plant I 200 10 210

Plant II 145 6 151

Plant III 64 8 72

Plant IV 155 12 167

Based on these inspection data,

A. What is probability of randomly selecting a disk drive from Plant II?

B. What is probability of randomly selecting a disk drive from Plant II or Plant III?

C. What is probability of working disk drive being received by computer Plants?

D. What is probability of randomly selecting a disk drive from Plant I and Plant IV?

E. What is probability of defective given that Plant I supplied the disk drive?

F. What is probability of working given that Plant III supplied the disk drive?

G. What is probability of Plant IV is not supplied given that working disk drive?