Math 50 – Section #3.4 Name ____________________
Histograms
Professor Jason Wang
1. A statistics teacher surveys some of the students in his statistics classes about
the number of hours they work per week and their responses are described in the
histogram below. Use this information to answer each of the following questions.
sentences.
(a) What variable is described by the histogram? Is it discrete or continuous?
(b) How many of the students work between 9 and 25 hours per week?
(c) How many of the students work at least 20 hours per week?
(d) What proportion of the students work less than 10 hours per week?

1. For each of the following histograms, describe the shape of each distribution.
2. The number of hours that some trigonometry students spent studying for their
first test are described by the density histogram below.
Use the information to answer each of the following questions.
(a) Compute the area of each of the
six bars in the density histogram.
(b) Find the total area of the six bars
(c) Explain why the total area of the bars of any density histogram is always
equal to the result you found in part (b).