Question

Read the paragraph.

In 1969, according to the federal government, only 60 percent of drinking water in the country met federal quality standards. Furthermore, between 1961 and 1970 the government noted over 46,000 illnesses caused by diseases found in drinking water. This led to the Safe Drinking Water Act, which was signed into law in 1974. Recently, the Environmental Protection Agency estimated that 90 percent of Americans now have drinking water that meets federal quality standards.

How has the Safe Drinking Water Act benefited public health?

It has decreased access to safe drinking water to 90 percent of the US population.
It has increased the number of people in the US with access to safe drinking water to 60 percent.
It has increased the proportion of the US population with access to safe drinking water by 30 percent.
It has increased the number of people in the US with access to safe drinking water by 90 percent.

Answer 1

It increased the proportion by 30 percentage points — from 60% to 90% of the population (choice 3).