You want to estimate the number of people in a town in favor of a proposed curfew law. You survey every fifth person who enters a post office. Is this biased or unbiased?

Our goal is to collect email addresses from 60% of customers who purchase a product." so that means if i talk to 95 customers, i need to persuade to provide an email address?

On a architect's drawing of a house, 1 inche representa 1.5

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9