Sampling and Experimentation

Questions about sampling and experimentation represent just 10% to 15% of the AP statistics multiple choice questions. The main sampling and experimentation topics are:
-Overview of methods of data collection: census, surveys, experiments, observational studies;
-Planning and conducting surveys: characteristics, populations, samples, random selection, sources of bias, simple random sampling, stratified random sampling and cluster sampling;
-Planning and conducting experiments: characteristics, treatments, control groups, random assignments, replication, sources of bias and confounding, placebo effect, blinding, randomized design, matched pairs design;

Examples of sampling and experimentation AP Statistics multiple choice questions:

1. A nutritional consulting company is trying to find what percentage of the population of a town is overweight. The marketing department of the company contacts by telephone 600 people from a list of the entire town's population. All 100 people give answers to the survey. Which of the following is the most significant source of bias in this survey?

a) Size of sample.
b) Undercoverage.
c) Voluntary response bias.
d) Nonresponse.
e) Response bias.

2. An opinion survey will be conducted at three corporations. Corporation A has 40,000 employees, corporation B has 60,000 employees and corporation C has 125,000 employees. The results of each survey will be used to estimate the opinions of employees at each corporation. Each survey will be conducted with a simple random sample of 500 employees. Which corporation will have its employees opinions estimated more accurately by the surveys?

a) Corporation A.
b) Corporation B.
c) Neither corporation will have a more accurate estimate.
d) Corporation C.
e) Corporations A and B.