a With the given information, you can calculate the percentage of students living in Ocean View that are seniors and non-seniors.
B
b We are only considering students living at Ocean View.
A
aDiagram:
B
b 25 %
Practice makes perfect
a We are investigating students living on East Coast College Campus. They can either live on Ocean View or elsewhere on campus. Also, they can either be seniors or non-seniors. We know that 10 % are seniors, which means 90 % are non-seniors. With this information, we can draw the following two-way table.
From the exercise we know that 60 % of all seniors live at Ocean View, and that 10 % of all student are seniors. We also know that 20 % of the non-senior students live at Ocean View. Since 10 % of students are seniors, 90 % must be non-seniors. With this information, we can fill out the boxes that describe students living at Ocean View.
When we know the number of seniors and non-seniors living at Ocean View, we can calculate how many seniors and non-seniors do not live at Ocean View by subtracting these values from 0.1 and 0.9, respectively.
Let's clean up the diagram.
b From the two-way table in Part A, we know that a total of 6 %+18 %=24 % live at Ocean View. With this information, we can find the probability that a randomly selected student at Ocean View is a senior.
6/24=0.25
There is a 25 % probability that a randomly selected student from Ocean View is a senior.
