SOLUTION: Surveyors asked a random sample of women in a major city what factor was the most important in deciding where to shop. The results appear in the following table. If the sample size

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Question 1176585: Surveyors asked a random sample of women in a major city what factor was the most important in deciding where to shop. The results appear in the following table. If the sample size was 1200, estimate with 95% confidence the proportion of women who identified price and value as the most important factor.
Factor Percentage (%)
Price and Value 40
Quality and selection of merchandise 30
Service 15
Shopping environment 15
Found 2 solutions by ewatrrr, Boreal:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!

Hi

n = 1200, p = .40 
95% confidence interval
ME = z%2Asqrt%28%28p%281-p%29%29%2Fn%29
ME = 1.96%2Asqrt%28%28.4%28.6%29%29%2F1200%29 = .0277
 .40 -.028 < p < .40 +.028
  (.37 , .43)

Wish You the Best in your Studies.


Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
price and value is 40% of the total (I misread the question)
95%CI half-interval is z*sqrt(p*(1-p)/n)
=1.96*sqrt(..4*.6/1200)
=0.0277
95%CI is (0.3723, 0.4277) units %