Question

In Exercises 29–36, answer the given questions, which are related to percentages.

Percentages in Advertising A New York Times editorial criticized a chart caption that described a dental rinse as one that “reduces plaque on teeth by over 300%.” What is wrong with this statement?

Short answer

A reduction of 300% in plaque is not meaningful.

Step-by-step solution

Given information

The caption in the chart states that a certain dental rinse reduces plaque on teeth by over 300%.

Interpretation of the percentage

The percentage value indicates that a particular portion is a percentage equivalent part of the whole unit. Assume the whole unit of 100% measurement when dividing into 100 equal portions. In this case, x% implies that the measurement of the segment is equal to x same-sized portions.

Identifying the error in the statement in terms of the study

It is stated that a dental rinse reduces plaque on teeth by more than 300%.

Here, 300% implies that the plaque reduces by three more times than the basic health condition of the teeth (no plaque).

This condition is not possible.

Thus, the claim in the advertisement is wrong.