THE INTERNATIONAL UNIVERSITY– VIETNAM NATIONAL UNIVERSITY – HCMC SCHOOL OF BUSINESS FINAL EXAMINATION Date: June 24, 2022 Duration: 90 minutes
Student ID: ..................................
Name:................................................
SUBJECT: Statistic for Business Dean of School Lecturers Signature: Signature: Dr. Nguyen Minh Tuan Dr. Nguyen Ba Trung GENERAL INSTRUCTION(S)
1) This is a closed book examination. However, students can bring only one 2-sided handwriting
A4 paper and hand-held calculators.
2) Electronic devices and mobile phone are strictly prohibited
3) No discussion and sharing Materials. 1
Please round the result to 4 decimals place, e.x 0.0001 Question 1: (25pts)
Arrivals of customers at a restaurant have a Poisson distribution with an average of seven per
hour. Let Y be the number of customers arriving per hour.
a) What is the expected value and the variance of Y?
b) Find the probability that no more than three customers arrive?
c) Find the probability that exactly five customers arrive?
d) What is the probability that exactly two customers arrive in the two-hour period of time
between a 1:00 P.M. and 3:00 P.M ?
ACBSP: Reflective Thinking
Topic: Probability distributions
Bloom's Taxonomy: Application and Analysis
Relevant Program Learning Outcomes: PLO1; PLO2, PLO4, PLO5, PLO8
Relevant Course Learning Outcomes: LO1, LO2, LO3
Level of Difficulty: Easy to Medium Question 2: (25pts)
The mean hourly pay rate for financial managers in the East North Central region is
$32.62, and the standard deviation is $2.32 (Bureau of Labor Statistics, September
2005). Assume that pay rates are normally distributed.
a. What is the probability a financial manager earns between $30 and $35 per hour?
b. How high must the hourly rate be to put a financial manager in the top 10% with respect to pay?
c. For a randomly selected financial manager, what is the probability the manager earned less than $28 per hour?
ACBSP: Reflective Thinking 2
Topic: Probability distributions
Bloom's Taxonomy: Application and Analysis
Relevant Program Learning Outcomes: PLO1; PLO2, PLO4, PLO5, PLO8
Relevant Course Learning Outcomes: LO1, LO2, LO3
Level of Difficulty: Medium Question 3: (25pts)
According to a 2014 Kaiser Family Foundation Health Benefits Survey released in 2015, the
total mean cost of employer-sponsored family health coverage was $16,834 per family per year,
of which workers were paying an average of $4823. A recent random sample of 25 workers from
New York City who have employer-provided health insurance coverage paid an average
premium of $6600 for family health insurance coverage with a standard deviation of $800. Make
a 95% confidence interval for the current average premium paid for family health insurance
coverage by all workers in New York City who have employer-provided health insurance
coverage. Assume that the distribution of premiums paid for family health insurance coverage by
all workers in New York City who have employer-provided health insurance coverage is
approximately normally distributed.
ACBSP: Reflective Thinking
Topic: Sampling distributions and Estimation
Bloom's Taxonomy: Application and Analysis
Relevant Program Learning Outcomes: PLO1; PLO2, PLO4, PLO5, PLO8
Relevant Course Learning Outcomes: LO1, LO2, LO3, LO4
Level of Difficulty: Easy to Hard Question 4: (25pts)
A past study claimed that adults in America spent an average of 18 hours a week on leisure
activities. A researcher wanted to test this claim. She took a sample of 12 adults and asked them
about the time they spend per week on leisure activities. Their responses (in hours) are as follows. 3 13.6 14.0 24.5 24.6 22.9 37.7 14.6 14.5 21.5 21.0 17.8 21.4
Assume that the times spent on leisure activities by all American adults are normally distributed.
Using a 10% significance level, can you conclude that the average amount of time spent by
American adults on leisure activities has changed?
ACBSP: Reflective Thinking
Topic: One-Sample Hypothesis Tests
Bloom's Taxonomy: Application and Analysis
Relevant Program Learning Outcomes: PLO1; PLO2, PLO4, PLO5, PLO8
Relevant Course Learning Outcomes: LO1, LO2, LO3, LO4
Level of Difficulty: Easy to Medium -------The End------ 4 5 6 7 8