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i forgot how to calculate 95% confidence interval?
there are 500 number of samples. 38 are defective. so the question is, 95% CI for this proportion defective is?
the answer is (0.053, 0.099) but i really want to know how to get there..
I've worked out the standard error for this, and it is 0.012 as sqrt*(pq/n), where p=(38/500)=0.076, q=1-0.076 =0.924
many thanks!
1 Answer
- ?Lv 79 years agoFavourite answer
n = 500
x = 38
p = 38/500
p = 0.076, q = 0.924
sqrt((1/500)*(0.076*.924)) = 0.0118510759
P(0.076 - 1.96*0.0118510759 < π < 0.076 + 1.96*0.0118510759) = 0.95
P(0.05277 < π < 0.09923) = 0.95, answer!
Source(s): Standardized Normal Distribution.