a pollster is going to sample a number of voters in a large city and construct a 90% confidence interval for the proportion who support the incumbent candidate for mayor. find a sample size so that the margin of error will be no larger than 0.05. be sure to round up to the next whole number.

A confidence interval, in statistics, refers to the chance that a population parameter can fall between a collection of values for a particular proportion of times.

Main body:

Finding Sample Size for Estimating a Population Proportion:

n = [tex]\frac{z}{M}^{2} }[/tex]p(1-p)

M = is the margin of error

p = is an estimated value of the proportion

We want to construct a 90% confidence interval for with a margin of error equal to 5%.

Because there is no estimate of the proportion given, we use p = 0.50 for a conservative estimate.

For a 90% confidence interval, z = 0.816

n = (0.816/0.05)^2 *0.5(1-0.5)

n = 266.3424*0.5*0.5

n = 66 approximately

Hence value of n = 66 .

To know more about confidence interval , visit:

https://brainly.com/question/15712887

#SPJ4