Question

A sample of adults less than 50 years old and adults greater than 50 years old were polled about relationships and one question on the survey asked, ‘In the past year, have you hidden any purchases from your spouse/partner?’ Twenty –three percent of a sample of 110 adults less than 50 years old said yes, while only 11% of a sample of 120 adults greater than 50 years old said yes.   Provide a confidence interval estimate for the true difference in proportions between adults under 50 and adults over 50 who have hidden a purchase from their spouse/partner in the last year. Use .05 signifcance level

Answer 1

Given datas

Total number of population (N)=110+120=230

No of Adults less than 50 year old (n1)=110

No of Adults greater than 50 year old(n2)=120

Propertion of first group said yes is

no of surviver for first group X1=110*0.23=25

Propertion of second group said yes d is

no of sample for second group X2=120*0.11=13

So Now we have to calculate at Confidence level=95%

Confidence interval will be

where S standard error

now

upper tailed value of

So the lower limit = 0.023

upper limit = 0.217

CI=(0.023 to 0.217)