Question

A) A certain region would like to estimate the proportion of voters who intend to participate in upcoming elections. A pilot sample of 25 voters found that 17 of them intended to vote in the election. Determine the additional number of voters that need to be sampled to construct a 95​% interval with a margin of error equal to 0.06 to estimate the proportion.

The region should sample ____ additional voters.

B) Determine the sample size needed to construct a 95​% confidence interval to estimate the average GPA for the student population at a college with a margin of error equal to 0.3. Assume the standard deviation of the GPA for the student population is 2.0.

The sample size needed is ____

C) Determine the sample size n needed to construct a 90​% confidence interval to estimate the population proportion when p BAR=0.62 and the margin of error equals 44​%.

n= ____

D) Determine the sample size n needed to construct a 90​% confidence interval to estimate the population mean when

sigma (σ)=29 and the margin of error equals 55.

n=____

E) According to a health organization in a certain​ country, 22.6​% of the population smoked in 2008. In​ 2014, a random sample of 750 citizens of this country was​ selected,152 of whom smoked. Complete parts a through c below.

a. Construct a 99​% confidence interval to estimate the actual proportion of people who smoked in this country in 2014.

A 99​% confidence interval to estimate the actual proportion has a lower limit of ____ and an upper limit of ____.

F) Determine the margin of error for a 95​% confidence interval to estimate the population proportion with a sample proportion equal to 0.70 for the following sample sizes.

a. n=125             

b. n=200            

c. n=260

a. The margin of error for a 95​% confidence interval to estimate the population proportion with a sample proportion equal to 0.70

and sample size n=125 is ____

Answer 1