SOLUTION: 5. Suppose that a market research firm is hired to estimate the percent of adults living in a large city who have cell phones. Five hundred randomly selected adult residents in t

Algebra ->  Statistics  -> Confidence-intervals -> SOLUTION: 5. Suppose that a market research firm is hired to estimate the percent of adults living in a large city who have cell phones. Five hundred randomly selected adult residents in t      Log On


   

Question 1174171: 5. Suppose that a market research firm is hired to estimate the percent of adults living in
a large city who have cell phones. Five hundred randomly selected adult residents in
this city are surveyed to determine whether they have cell phones. Of the 500 people
sampled, 415 responded yes - they own cell phones. Using a 95% confidence level,
compute a confidence interval estimate for the true proportion of adult residents of this
city who have cell phones.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi,
    x̄  = 415/500 = .83   n = 500
 Using a 95% confidence level, compute a confidence interval estimate
 for the true proportion of adult residents of this city who have cell phones. 
 
   ME = z%2Asqrt%28%28p%281-p%29%29%2Fn%29

   ME = 1.96%2Asqrt%28%28%28.83%29%28.17%29%29%2F500%29%29 = .0006

    .83 - .0006 < mu < .83 + .0006
       
Wish You the Best in your Studies.

CI	z = value
90%	z =1.645
92%	z = 1.751
95%	z = 1.96
98%	z = 2.326
99%	z = 2.576