Question

3) Afra has taken 200 items in a factory, and found that 12 of them are defective. What is the percentage of all defective products in that factory if Afra is supposed to provide the result with 90% confidence?

Answer 1

given data and necessary calculations are:-

sample size (n) = 200

sample proportion () = 12/200 = 0.06

z critical value for 90% confidence level, both tailed test be:-

the 90% confidence interval of the proportion of defectives be:-

Afra can be 90% confident that the the pecenatge of all defective products in that factory will be within  3.24 % to 8.76 % .

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