Question

Feeling sleepy? Students in a high school statistics class responded to a survey designed by their teacher. One of the survey questions was “How much sleep did you get last night?” Here are the data (in hours):

Part (a). Make a dotplot to display the data.

Part (b). Experts recommend that high school students sleep at least 9 hours per night. What proportion of students in this class got the recommended amount of sleep?

Short answer

Part (a)

Part (b) 0.1785

Step-by-step solution

Part (a) Step 1. Given information.

A survey designed by their teacher was completed by students in a high school statistics class.

Part (a) Step 2. Create a number line.

Put a dot above the corresponding number on the number line for each given data value.

Part (b) Step 1. This class's students got the recommended amount of sleep.

We can see in the dotplot that there are three dots at nine, one at ten, and one at eleven, for a total of five dots that correspond to at least nine hours of sleep per night.

Furthermore, we note that there are 28 dots in total in the dotplot, implying that 5 of the 28 students in the study slept at least 9 hours per night.

$\frac{5}{28}\approx 0.1785$

Thus, 0.1785 of the students in the study slept for at least 9 hours per night.