Question

Margin of Error. The following summaries of statistical studies give a sample statisticand a margin of error. Find the confidence interval and answer any additional questions.A Gallup poll found that 36% of Americans favor a law banning the manufacture, sale,and possession of semi-automatic (assault) rifles (down from 60% in 2000). The margin oferror was 4 percentage points. Is it reasonable to claim that one-third of Americans supportsuch a law? Explain.

Answer 1

As it is a Gallup poll, this is statistically representative.

A margin of error of 4% indicates that the real result of the poll is between

$\begin{gathered} 36+4=40 \\ \text{and} \\ 36-4=32 \end{gathered}$

32% and 40%.

Therefore, it is quite likely that a bit more than 1/3 of Americans support the banning law. The answer could be no, though it is open to interpretation as no further parameters to measure the reasonability of the claim were given.