Question

According to a​ report, 51.6​% of murders are committed with a firearm. ​(a) if 200 murders are randomly​ selected, how many would we expect to be committed with a​ firearm? ​(b) would it be unusual to observe 122 murders by firearm in a random sample of 200 ​murders? why?

Answer 1

a) 103, b) No

Explanation:

a) We need to multiply the probability by the amount of the sample to get:

200 × 51.6% = 103.2, rounded down to 103

b) As we have selected the people randomly, we have no control over the type of people we are given - this is theoretical and the estimate is not definite - all of the sample could have murdered by firearm or even none (even though it is highly unlikely).