A poll of 855 home sellers found that 28.7%…

Question

A poll of 855 home sellers found that 28.7% were trying to sell their home without a real estate agent. The margin of error for this poll was 3.6%. Find the approximate confidence level used by the pollsters.

Ans: ______% (Enter one of the following: 80,90,95,98,99)

Answer 1

We have Margin of ERROR formula :

E = Z *√p* (1-p)/n .............(A)

we have to find value of Z then from Z , we will calculate Confidence interval

Given

n = 855

E = 3.6 % = 3.6/100= 0.036

p = 28.7 % = 0.287

By putting values in (A), we have

0.036 = Z * √0.287 * (1-0.287)/855

0.036 = Z * 0.01547

Z = 0.036/0.01547

Z = 2.3270

Z = 2.3270, critical value for 98% confidence level.

Therefore, the approximate confidence level u: pollsters=98%