Question

Approximately 9 out of every 50 people who saw a movie this week say they watched it on Netflix. Suppose we want to find the probability that a randomly selected movie-goer saw a movie on Netflix this weekend. Express that probability in three ways: As a fraction, a proportion, and a percentage.

Answer 1

Answer:

• 1. As a fraction: 9/50

• 2. As a proportion: x/1 = 9/50

• 3. As a percentage: 18%

Explanation:

1. As a fraction:

Depart from the definition of probability: probability is the number of favoragle outcomes divided by the total number of possible outcomes:

• Probability = number of movie-goers who say they watched a movie on Netflix this week / number of movie-goers that saw a movie this week

• Probability = 9 / 50

2. As a proportion:

A proportion is the equality of two ratios. In this case you must set the ratio of people who say they watched it on Netflx, x, per every people who saw a movie this week, 1, equal to the ration 9 /50.

Hence, the proportion that shows the probability is:

• x / 1 = 9 / 50

Where x is the probability.

3. As a percentage

You just have to multiply the probability by 100:

• (9/50) × 100 = 18%