10.4 Proportions

# A n before n after survey conducted point d pafter

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Unformatted text preview: + error α n n 1 2 p( −p) p( −p) interval 11 1 21 2 d±z 2 + α estimate n n 1 2 Example Given these samples, what is the interval estimate for the difference in awareness of the product? Hypothesis Tests Market Research(1 - p1 ) p2 (1 - p2 ) p1 Difference Between 2 d is conducting + Associates ± za 2 n1 n2 Population Proportions research to evaluate the effectiveness pBeforeclient’s new pAfter (1 - pAfter ) of a (1 - pBefore ) D = p1 – p2 parameter = d ± za + advertising2campaign. A n Before n After survey conducted point d = pAfter - pBefore = 0.08 immediately after the.4 (1 - .4 ) .48(1 - .48)stimator new e = - 0 08 ± 1.96 campaign .showed 120 150 of + out 250 standard p( −p) p ( −p ) 11 1 21 2 250 households “aware” of σ= + = - 0.08 ± 0.0999 error d n n 1 2 the client’s product. 0.1799 £ D £ 0 Before the -new campaign.0199 p( −p) p ( −p ) margin of 11 1 21 2 began, a telephone survey 0.02 - 0.18 £ D £ of z2 + error α n n 1 2 150Hence, the 95% confidence interval for households in the test market difference in before and after p( −p) p( −p) interval...
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