Question

If 30 people claimed that they get an average of seven hours of sleep, how many people claimed that they get at least eight hours of sleep each night? [Type your answer as a number.]

Answer 1

60 people claimed they they got at least eight hours of sleep.

Answer 2

78 people claimed that they get at least eight hours of sleep each night.

Explanation:

We know that 30 people claimed that they get an average of seven hours of sleep. Using the circular diagram, we find that these 30 people represent 25% of the total number of people.

According to the graph, people that get at least eight hours of sleep each night represent 65%, that is, 50% of the people sleep eight hours and 15% sleep nine or more.

Then, we use the rule of three, if 30 people represent 25% of the total, how many people would represents 65%?

`x=65\%(30 \ people)/(25 \%) = 78 \ people`

Therefore, 78 people claimed that they get at least eight hours of sleep each night.