4. A survey of 35 individuals reveals that the proportion of people in a residential area who patronize a particular supermarket is 0.42; a repeat of the survey in the following year, using 52 individuals finds that the proportion is 0.56. Find a 95% confidence interval for the difference in sample proportions. (3)
PLEASE HELP!
Solution :
Given that,
n1 = 35
1 = x1 / n1 = 0.42
n2 =52
2 = x2 / n2 = 0.56
1) Point estimate of difference between two proportions
= 1 - 2
= 0.42 - 0.56
= -0.14
2)
Our aim is to construct 95% confidence interval.
= 1.96 (use z table)
Margin of error = *
=
= 0.212
3) Required interval is
Point estimate Margin of error
-0.14 0.212
(-0.14 - 0.212, -0.14 + 0.212)
(-0.352 , 0.072)
Get Answers For Free
Most questions answered within 1 hours.