Of 125 adults selected randomly from one town,28 of them smoke.Construct a 99% confidence interval for the percentage of all adults in the town who smoke.

A) (15.1%,29.7%)
B) (13.7%,29.7%)
C) (12.8%,30.3%)
D) (16.2%,28.6%)
E) (13.7%,31.1%)

Question

Lindsey Peters · Accepted Answer

Final Answer : C, Explanation :  We need to use the formula for the confidence interval of a proportion:p̂ ± z*√(p̂(1-p̂)/n)where p̂ is the sample proportion (28/125), n is the sample size (125), and z* is the appropriate z-score for the desired confidence level.For a 99% confidence level, the corresponding z-score is 2.576.Calculating the interval:28/125 ± 2.576*√((28/125)*(1-28/125)/125)gives us (12.8%,30.3%). Therefore, the answer is choice C.

Of 125 adults selected randomly from one town,28 of them smoke.Construct a 99% confidence interval for the percentage of all adults in the town who smoke.

A) (15.1%,29.7%)
B) (13.7%,29.7%)
C) (12.8%,30.3%)
D) (16.2%,28.6%)
E) (13.7%,31.1%)

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Of 125 adults selected randomly from one town,28 of them smoke.Construct a 99% confidence interval for the percentage of all adults in the town who smoke.A) (15.1%,29.7%) B) (13.7%,29.7%) C) (12.8%,30.3%) D) (16.2%,28.6%) E) (13.7%,31.1%)

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Learning Objectives

Learning Objectives

Related questions

Of 125 adults selected randomly from one town,28 of them smoke.Construct a 99% confidence interval for the percentage of all adults in the town who smoke.

A) (15.1%,29.7%)
B) (13.7%,29.7%)
C) (12.8%,30.3%)
D) (16.2%,28.6%)
E) (13.7%,31.1%)