In the Health ABC Study, 520 subjects owned a pet and 1962 subjects did not. Amo
ID: 3176484 • Letter: I
Question
In the Health ABC Study, 520 subjects owned a pet and 1962 subjects did not. Among the pet owners, there were 300 women; 953 of the non-pet owners were women. Find the proportion of pet owners who were women. Do the same for the non-pet owners. (Be sure to let Population 1 correspond to the group with the higher proportion so that the difference will be positive. Round your answers to three decimal places.)
Give a 95% confidence interval for the difference in the two proportions. (Do not use rounded values. Round your final answers to three decimal places.)
(____,____)
p1 = p2 =Explanation / Answer
p1=300/520=0.5769 ; n2=520
p2=953/1962 =0.4857
std error of difference =(p1(1-p1)/n1+p2(1-p2)/n2)1/2 =0.024
for 95% CI, z=1.96
hence confidence interval =(p1-p2)+/- z*std error =0.043 ; 0.139