Question

Lactose intolerance causes difficulty digesting dairy products that contain lactose (milk sugar). It is particularly common among people of African and Asian ancestry. In the United States (ignoring other groups and people who consider themselves to belong to more than one race), 82% of the population is white, 14% is black, and 4% is Asian. Moreover, 15% of whites, 70% of blacks, and 90% of Asians are lactose intolerant. Step 1:
What percent of the entire population is lactose intolerant?
Give your answer in percents to 1 decimal place (e.g., 22.4).

Step 2:
What percent of people who are lactose intolerant are Asian?
Give your answer in percents as a whole number (e.g., 20).

Answer 1

Answer:

1) 25.7% of the population is lactose intolerant.

2) 14% of the lactose intolerant people is Asian

Step-by-step explanation:

Population distribution according to race:

• 82% white
• 14% black
• 4% Asian

Lactose intolerance of races

• 15% of whites
• 70% of blacks
• 90% of Asians

Assume US population consists of 1000 people.

820 people are white, 140 people are black and 40 people are Asian.

Then 15% of 820 white, 70% of black, 90% of Asian is lactose intolerant.

• 15% of 820 is 123, which gives the white lactose intolerant people

• 70% of 140 is 98, which gives the black lactose intolerant people

• 90% of 40 is 36, which gives the Asian lactose intolerant people.

Step1

Then total lactose intolerant people in the US population is 123+98+36=257

Total population is 1000 people, therefore $\frac{257}{1000}$=25.7% of the population is lactose intolerant.

Step2

There are 36 Asian lactose intolerant people. Total lactose intolerant people is 257. $\frac{36}{257}$ = 14% of them is Asian.