Question

Country Financial, a financial services company, uses surveys of adults age 18 and older to determine if personal financial fitness is changing over time (USA Today, April 4, 2012). In February of 2012, a sample of 1000 adults showed 410 indicating that their financial security was more than fair. In February of 2010, a sample of  900 adults showed 315 indicating that their financial security was more than fair.

What is a 99% confidence interval estimate of the difference between the proportions at the two years, 2012 and 2010?

Group of answer choices

A.(LCL, UCL) = (2.08, 5.84)

B.(LCL, UCL) = (1.49, 6.43)

C.(LCL, UCL) = (0.81, 7.11)

D.(LCL, UCL) = (2.38, 5.54)

Answer 1

Given:

n1 = 1000 x1 = 410

n2 = 900 x2 = 315

Significance level, = 1-0.99 = 0.01

Therefore the 99% confidence interval estimate of the difference between the two population proportion is (0.0025, 0.1175)