Question

john and lauren are looking for a good neighborhood to raise their children. they want neighbors who have kids and who are fellow rollerbladers as well. the couple surveys a random sample of residents in a particular neighborhood. their results are in the table. david, anastasia, and miles live in the neighborhood. david does not have children. anastasia has never rollerbladed, all we know about miles is that he is very tall. rounded to the nearest hundredth, what is the probability that miles is a rollerblader?
kids no kids row total
rollerblader 41 9 50
not a rollerblader 3 9 12
column total 44 18 62

Explanation:

Step1: Find total number of residents

The total number of residents in the sample is the grand - total of the table, which is 62.

Step2: Find number of rollerbladers

The number of rollerbladers is the row - total for "Rollerblader", which is 50.

Step3: Calculate probability

The probability $P$ that a randomly selected resident is a rollerblader is the number of rollerbladers divided by the total number of residents. So $P=\frac{50}{62}\approx0.81$.

Answer:

0.81