1) Identify the types of sampling errors that exist in the following sampling designs.

1. A radio show asks people to phone in their views on whether the United States should house the homeless.
2. The student newspaper plans to make a prediction for the student council election based on a survey of its readers.
3. A new gym chooses to survey the first 20 members who enter the facility one day to determine whether members favor the new elliptical machines.

a) voluntary; II, nonresponse; III, convenience

b) nonresponse; II, voluntary; III, convenience

c) nonresponse; II, convenience; III, voluntary

d) voluntary; II, convenience; III, nonresponse

e) convenience; II, voluntary; III, nonresponse

2.An experiment was conducted to evaluate the success of a methicillin-resistantStaphylococcus aureus(MRSA) vaccine. MRSA can be prevented if subjects wash their hands regularly. The subjects were treated, but only some of the vaccines were successful. The researchers are unsure whether this was a result of hand washing or the vaccine alone. What is this an example of?

a) Confounding

b) The placebo effect

c)Blinding

d)Replication

e)Bias

3.Sleep is known to affect student grades. Kirsten is conducting a study in a local high school using two treatments on two groups of students. One group will nap one hour in an eight-hour school day and another will nap 30 minutes in an eight-hour school day. What group would be the best control for the study?

a)A third group that takes a one-hour nap or a 30-minute nap randomly each day

b)A third group that shortens the school day to six hours

c)A third group in which no naps occur

d)A third group that splits the day with a 30-minute nap in the morning and a 30-minute nap in the afternoon

e)A third group in which each student chooses either a 30-minute nap or a one-hour nap