Question

Tell what number is always used when you use a proportion to solve a percent problem. Explain.

A) The proportion used in solving a percent problem always involves the number 100 because a percent is a ratio out of 100.

B) The proportion used in solving a percent problem always involves the number 10 because percents are based on a scale of 10.

C) The proportion used in solving a percent problem always involves the number 1 because percents are a way of expressing fractions.

D) The proportion used in solving a percent problem does not involve any specific number; it varies based on the problem's context

Answer 1

The number always used when using a proportion to solve a percent problem is 100, because percent means per hundred. It is represented in proportions as a ratio with a denominator of 100, essential in percentage calculations for comparisons or finding parts of a whole.

Step-by-step explanation:

The number always used when using a proportion to solve a percent problem is 100. This is because a percent is a ratio whose denominator is 100. For instance, if we say 50%, it means that for every 100 parts, 50 of those parts are being considered. Thus, the proportion looks like 50/100. This can be simplified to 1/2. When solving percent problems, such as finding a certain percentage of a number, we can set up a proportion where one side is the percent over 100 and the other side represents part of a total quantity over that total quantity.

Example:

To find what is 25% of 80, set up the proportion where 25/100 = x/80, and solve for x. This would be 0.25 * 80 = x or x = 20. Hence, 25% of 80 is 20.