# Conditional Probability a random survey was taken to gather information about grade level and car ownership status of students at a school. This table shows the results of the survey. Write your answer as a reduced fraction

 Date 08.07.2018 Size 37.63 Kb.

GSE Geometry Unit 7 – Probability 7.5 – Homework

Name: ___________________________________________ Date: ____________________________

Conditional Probability

A random survey was taken to gather information about grade level and car ownership status of students at a school. This table shows the results of the survey. Write your answer as a reduced fraction.

 Owns a Car Does Not Own a Car TOTAL Junior 6 10 16 Senior 12 8 20 TOTAL 18 18 36

1. Find the probability that a randomly selected student will be a junior, given that the student owns a car.

1. Find the probability that a randomly selected student will own a car, given that the student is a senior.

The table below shows numbers of registered voters by age in the United States in 2004 based on the census. Find each probability in decimal form, 2 places.

 Age Registered Voters (in thousands) Not Registered to Vote (in thousands) 18–24 14,334 13,474 25–44 49,371 32,763 45–64 51,659 19,355 65 and over 26,706 8,033

1. Find the probability that a randomly selected person is registered to vote, given that the person is between the ages of 18 and 24.

1. Find the probability that a randomly selected person is not registered to vote, given that they are 65 and over.

1. Find the probability that a randomly selected person is between the ages of 45 and 64 and is not registered to vote.

A faculty advisor at Ridge High School surveyed 100 students about their preference for a social event. Of the 100 students surveyed, 50 were tenth graders and 50 were eleventh graders. Of the tenth graders, 30 chose a bowling party and 20 chose a dance. Of the eleventh graders, 20 chose a bowling party and 30 chose a dance.

1. Make a two way frequency table to represent the data.

1. Based on your answers on #7 & 8, do you think that the probability of liking bowling is dependent (different answers) on whether a student is in the 10th or 11th grade?

After growing tired of squinting while driving, Dwayne went shopping for a pair of sunglasses. He tried on glasses with different frames and lenses. He tried on 15 pairs of glasses, 8 that were cat eye frames and 7 that were browline frames. 2 of the cat eye frames were polarized lenses. He also tried on 10 regular lenses.

1. Make a two-way frequency table to represent the data.

 Polarized (P) Regular (R) Cat Eye (C) Browline (B)

1. What is the probability that a randomly selected pair of sunglasses has regular lenses, given that the pair of sunglasses has cat eye frames?