Exam 13: Determining the Size of a Sample

Jack McCombs is the owner of several Firehouse Subs sandwich shops in Anytown. He has been spending $200,000 a year in various media in Anytown in an attempt to build awareness of his stores. Instead of continuing to spend the same amount on advertising every year, Jack wants an assessment as to what he has gained from the advertising he has paid for. He is interested in knowing what percentage of the population in Anytown is aware of his store's name, menu, and locations three factors for which he has attempted to build awareness. His advertising agency quoted him a price for a survey and told him they would use a sample size of 150, and that they were assuming 35 percent of the respondents would be aware of his advertising. Jack was reluctant to use the advertising agency to conduct the survey. He felt like he needed another firm so as to avoid any conflict of interest. He found a marketing researcher in town who was certified as a CPR by the Marketing Research Association. The CPR asked Jack how accurate he wanted the results of the survey to be. Jack said he wanted the percentage to be within ±3 percent of the real population percentage. Assuming he wanted to be 95 percent confident of the accuracy of the results, the CPR used the following formula to determine the accuracy of the survey recommended by the ad agency: ± sample error percent = 1.96 ∗ the square root of pq/n. Using the formula, what would be the sample error if Jack were to use the ad agency survey recommendation?

When all other factors are held constant, as we increase the level of accuracy, the sample size and the cost of a marketing research survey are best characterized by which of the following?

In a "Yes/No" question, 50 percent "Yes" and 50 percent "No" shows less variability than does 90 percent "Yes" and 10 percent "No."

Large sample size bias refers to a belief that sample size determines a sample's representativeness.

Sample size is related to the size of the confidence interval in that:

The basic difference between an arbitrary and a conventional sample size determination is that:

In trying to estimate the variability in the population in order to determine pq, which of the following represents viable alternatives?

The axiom: "You can take any finding in the survey, replicate the survey with the same probability sample size, and you will be very likely to find the same finding within the +/- percent range of the original finding" is based on the idea of the confidence interval.

Which of the following is NOT a component needed for SSI's Formula for determining how many telephone numbers are needed?

Nonsampling error pertains to all sources of error other than the sample selection method and sample size.

Sources of error that come from sources other than the sample selection method and sample size are referred to as:

If you were conducting a telephone survey of households using random digit dialing numbers and you determined that you needed a sample size of 1,100, which of the following would be most accurate?

A random sample must be perfectly accurate to be considered a very good representation of the population.

The only perfectly accurate sample is a census.

Which of the following is the most correct method of determining sample size?

If we assume the "highest" amount of variability when estimating pq, then pq are:

Sampling error is the difference between the sample findings and the findings that the client expected to have prior to the survey.

The arbitrary approach to sample size determination takes the desired level of accuracy into account.

95 percent of the observations under the normal curve fall within ________ times the sample error.

Political Research Associates has been hired to conduct a survey to determine the percentage of voters. If the election were held today, who would vote for Candidate X for president? Candidate X has not even announced her candidacy for president and there are no previous surveys that would indicate voter preferences. Still, Political Research Associates must estimate the variance in the population in order to determine the size of the sample they need for their survey for Candidate X. Which of the following would be the wisest choice for estimating variance?