A Harris poll surveyed 2,320 adults in the United States, among which 14% said that they have at least one tattoo. The margin of error is 2 percentage points.

a. Interpret the margin of error by identifying the range of values likely to contain the percentage of adults with tattoos.

b. Identify the population.

c. Is this study an experiment or an observational study? Explain. Identify the variable of interest.

d. Is the reported value of 14% a population parameter or a sample statistic? Why?

e. If you learned that survey subjects responded to a magazine article asking readers to phone in their responses, would you consider the survey results to be valid? Why or why not?

f. Describe a procedure for selecting the survey subjects using a simple random sample.

g. Describe a procedure for selecting similar survey subjects using stratified sampling.

h. Describe a procedure for selecting similar survey subjects using cluster sampling.

i. Describe a procedure for selecting similar survey subjects using systematic sampling.

j. Describe a procedure for selecting similar survey subjects using a convenience sample.