# STAT 213 Study Guide - Final Guide: Poisson Distribution, Standard Deviation, Minitab

46 views9 pages

Published on 24 Jun 2019

School

Department

Course

Professor

UNIVERSITY OF CALGARY

Department of Mathematics and Statistics

Prepared by: Dr. Bingrui (Cindy) Sun

STAT 213 Supplementary Questions Spring 2019 Total: 58 marks

First Name: Last Name:

UC ID:

1. A polygraph test is used to determine if someone is lying. The test is not totally reliable:

15% of people who are not lying give a test result that they are lying, while 10% of people who

are lying give a test result that they are not lying. A congressman who is known to lie 30% of

the time is tested. Final answer in 4 decimals. (Total 7 marks)

(a) What is the probability that he is correctly classiﬁed as being lying? (3 marks)

(b) If the polygraph test says he is lying, what is the probability that he could actually be

telling the truth? (4 marks)

1

2. The screen shot below is made from the Statistics Canada website. http://www.statcan.gc.ca/tables-

tableaux/sum-som/l01/cst01/famil50a-eng.htm (Total 7 marks)

(a) Compute the average number of children at home per family in the ‘Female lone-parent’

category. Use ‘4 children’ as an approximation for ‘3 or more children’. Final answer in 2

decimals. (3 marks)

2

(b) Compute the standard deviation of the number of children at home per family in the

‘Female lone-parent’ category. Use ‘4 children’ as an approximation for ‘3 or more children’.

Final answer in 2 decimals. (4 marks)

3. Let’s assume that at the University of Calgary, international students make up 10% of the

undergraduate student population. Suppose 30 University of Calgary undergraduate students

are randomly selected, how likely will there be fewer than four international students? Final

answer in 4 decimals. (Total 4 marks)

3