Question

A survey research company uses random digit dialing. They have a contract, to estimate the percentage of people watching Spanish-language television in several Southwestern cities.They took a sample of 1,000 in Austin, Texas–which has about 600,000 residents. They are satisfied with the accuracy of the estimates for Austin. Dallas has about twice the population of Austin, but similar demographics. To get about the same accuracy in Dallas as in Austin, how large a sample size should the company use?

A. 1000/2 = 500

B. 1000/√2 = 707

C. 1000D.√2×1000 = 1414

E. 2×1000 = 2000

Justify your answer.

(b) The Census Bureau is planning to take a sample amounting to 1/10 of 1% of the population in each state to estimate the percentage of the population in that state earning over $100,000 a year. Other things being equal:

A. The accuracy to be expected in California (population 35 million) is about the same as the accuracy to be expected in Nevada (population 2 million).

B. The accuracy to be expected in California is quite a bit higher than in Nevada.

C. The accuracy to be expected in California is quite a bit lower than in Nevada.

Justify your answer.

Answer 1