Essential Statistics
5.2 Assignment #2
Name:______________________________________
1. For the lottery ticket example on the notes, could it happen that one random sample finds that
57% of adults recently bought a lottery ticket and a second random sample find that only 37%
had done so? Would you be surprised if a smaller sample from this population gave 57%?
Would you be surprised if the smaller sample gave 37%?
2. Just before a presidential election, a national opinion poll increases the size of its weekly sample
from the usual 1500 people to 4000 people.
a. Does the larger random sample reduce the bias of the poll result? Explain.
b. Does it reduce the variability of the results? Explain.
3. The Ministry of Health in the Canadian province of Ontario want to know whether the national
health care system is achieving its goals in the province. Much of the information about health
care come from patient records, but that source doesn’t allow us to compare people who use
health care services with those who don’t . So, the Ministry of Health conducted the Ontario
Health Survey, which interviewed a random sample of 61,239 people who live in the Province of
Ontario.
a. What is the population for this sample survey? What is the sample?
b. The survey found that 76% of males and 86% of females in the sample had visited a
general practitioner at least once in the past year. Do you think these estimates are
close to the truth about the entire population?
Essential Statistics
5.2 Assignment #2
Name:______________________________________
4. 10 out of 25 club members listed below are female (marked with an asterisk). The club chooses
5 members at random to receive free trips to the national convention.
Alonso
Darwin
Herrnstein
Myrdal
Vogt*
Binet*
Epstein
Jimenez*
Perez*
Went
Blumenbach
Ferri
Luo
Spencer*
Wilson
Chase*
Gonzalez
Moll*
Thomson
Yerkes
Chen*
Gupta
Morales*
Toulmin
Zimmer
a. Draw 20 SRSs of size 5, using your calculator each time. Record the number of females
in each of your samples.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
b. What is the average number of females in your 20 samples?
c. Do you think the club members should suspect discrimination if no one of the 5 tickets
for to women?