Question

The Centers for Disease Control reported the percentage of people 18 years of age and older who smoke (CDC website, December 14, 2014). Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .15. a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of .03 with 99% confidence?

round z or t value to 3 decimal places

Answer 1

Solution Page 1 0.15 Given proportien who smoke of The proportion p=0.15 w the sample dize to estimate the propostion of smokers in the population with a margin of enor of 0.03 when 99% conja dence level as determined We know that margin of Error (moe). Za PCI-P) Now at a=0.05 level of significance, the Critical value oft is calculated from the Wabu u Zell = 0.025 1.96 Now, MOE -0.03 - (1708)z Plit

2 - za pi-p) inst " (MDE)2 1 = (1.96)’x 0.15 (1-0.15) (0:03)2 * 3.8H16X 0.1275 0.0009 n = 544.2266667 n řsuu :: Disuu. Sample is required to estimate the proportion of smokers in the population with a margin of enor of 0.03.