1. Intro to Stats and Collecting Data

Identify the sampling technique used, and discuss potential sources of bias (if any). Explain.

Law enforcement officials stop and check the driver of every third vehicle for blood alcohol content.

You want to know the favorite spring break destination among 15,000 students at a university. Determine whether you would take a census or use a sampling. If you would use a sampling, determine which sampling technique you would use. Explain your reasoning.

[DATA] Chicago High Schools Open the data set 1_3_17 from www.pearsonhighered.com/sullivanstats. The data set represents a list of every high school in the city of Chicago. Suppose you wish to conduct a survey of all the students enrolled for a simple random sample of 8 high schools in the city of Chicago. Record the name of the 8 high schools (individuals) selected. Write a description of the process you used to generate your sample.

Describe a circumstance in which stratified sampling would be an appropriate sampling method.

Which sampling method does not require a frame?

A(n) _______ sample is obtained by dividing the population into groups and selecting all individuals from within a random sample of the groups.

True or False: A simple random sample is always preferred because it obtains the same information as other sampling plans but requires a smaller sample size.

True or False: When conducting a cluster sample, it is better to have fewer clusters with more individuals when the clusters are heterogeneous.

True or False: Inferences based on voluntary response samples are generally not reliable.

True or False: When obtaining a stratified sample, the number of individuals included within each stratum must be equal.

Stratified Sampling The owner of a private food store is concerned about employee morale. She decides to survey the managers and hourly employees to see if she can learn about work environment and job satisfaction. From the list of workers at the store, obtain a stratified sample of two managers and four hourly employees to survey.

Systematic Sample To predict the outcome of a county election, a newspaper obtains a list of all 945,035 registered voters in the county and wants to conduct a systematic sample.

Determine k if the sample size is 130.

Sample Design A school board at a local community college is considering raising the student services fees. The board wants to obtain the opinion of the student body before proceeding. Design a sampling method to obtain the individuals in the sample. Be sure to support your choice.

Sample Design A pharmaceutical company wants to conduct a survey of 30 individuals who have high cholesterol. The company has obtained a list from doctors throughout the country of 6600 individuals who are known to have high cholesterol. Design a sampling method to obtain the individuals in the sample. Be sure to support your choice.

Putting It Together: Comparing Sampling Methods Suppose a political strategist wants to get a sense of how American adults aged 18 years or older feel about health care and health insurance.

In a political poll, what would be a good frame to use for obtaining a sample?