Question

33. The table to the right shows the results of a survey in which 400 adults from the East, 400 adults from theSouth, 400 adults from the Midwest, and 400 adults from the West were asked if traffic congestion is a serious problem. Complete parts (a) and (b).

Region Percentage

East 35%

South 32%

Midwest 26%

West 53%

(a) Construct a 99% confidence interval for the proportion of adults from the East who say traffic congestion is a serious problem.

The 99% confidence interval for the proportion of adults from the East who say traffic congestion is a serious problem is ( ___,____ ) (Round to three decimal places as needed.

(b) Construct a 99% confidence interval for the proportion of adults from the East who say traffic congestion is a serious problem. Is it possible that these two proportions are equal? Explain your reasoning. The 99% confidence interval for the proportion of adults from the East say traffic congestion is a serious problem is:?

(round to three decimal places as needed)

Answer 1

(a)

n = 400

p = 0.35

q = 1 - p = 0.65

SE =

= 0.01

From Table, critical values of Z = 2.576

Confidence interval:

p Z SE

= 0.35 (2.576 X 0.0238)

= 0.35 0.0614

= (0.289 , 0.411)

The 99% confidence interval for the proportion of adults from the East who say traffic congestion is a serious problem is (0.289, 0.411).

(b)

Question (b) is identical to Question (a) - May be typographical error in typing the questions.