Bar Graphs and Histograms Examples

Tim gets $5 per week, Penelope gets $10 per week, and Lu gets $7 per week. Not because Penelope is older or works the hardest. Her parents just like her best.

Compare the weekly allowances of the children using a bar graph.

In this case, the "bins'' are the children's pockets, and the quantity in each child's pocket will be in dollars:

The height of the bar above Tim's name will be 5, since Tim gets $5, and so on:

The salaries of three employees are compared in the bar graph below. Use the bar graph to answer the questions.

1. Who makes the most money?
2. How much more money per year does Sr. Lopez make than Mr. Jones?
3. Who makes $50,000 per year?
4. Hey Mr. Smith, can we borrow $100?

1. Mr. Smith. 
2. $50,000. 
3. Mr. Jones.
4. "No, make your own way in life. I earned this money." Well, okay then.

Different cats were weighed. We had a tough time getting them all to sit on the scale without scratching us half to death. Anyway, we finally found them to have the following weights, in pounds.

.

(a) Draw a histogram for the data with interval 1 pound.
(b) Draw a histogram for the data with interval  pound.

(a) Draw a histogram for the data with interval 1 pound.

Let's make intervals of one pound, tally up the data, and see what we find.

Now we can use these tallies to build a histogram:

(b) Draw a histogram for the data with interval  pound.

Again, we tally up the data:

and use that tally to draw a histogram:

We can see that the weights of the cats are pretty evenly spread out. Just like the bellies on a couple of those 14-pounders. Oof.

Use the histogram to answer the following questions.

1. How many kids are at least 5' but not more than 5'3''?
2. How many kids are at least 5' but not more than 5'6''?
3. Was there a kid of height 6' in the data set?
4. Must there have been a kid with height exactly 5' in the data set?

1. 2. 
2. There are 2 between 5' and 5'3'' and 5 more between 5'3'' and 5'6'', for a total of 7.
3. No. Such a kid's height would have been counted in a bin from 6' to 6'3''. We also might have suspected it was an adult masquerading as a kid. 6' is tall for a young 'un.
4. No. There were 2 kids between 5' and 5'3'', but they could have both been 5'1'' or something.