Question

Tom surveyed 150 students at his school to find out each student's favorite color. His results are shown in the circle graph above. Candace asked 15 of her friends from the same school to choose their favorite color, and 5 people chose yellow. According to Tom's survey, how many of Candace's friends would have been expected to choose yellow?

Answer 1

We have that in Tom's survey he obtained that 20% of the students like the yellow color (see graph above).

Then, in Candance's (small) survey, she asked 15 friends. According to Tom's survey, Candance should have obtained that 20% of her friends like the yellow color.

Therefore, we need to find 20% of 15 (friends) to find the expected number of friends that Candance should have had using the results of Tom's survey. Then, we have:

`(20)/(100)\cdot15=(300)/(100)=3`

Hence, according to Tom's survey, Candance's friends would have been expected to be 3 to choose (of her 15 friends) yellow (3 is 20% of 15).