Essential Statistics
Dotplots & Stemplots
Name:_____________________________
1. Suppose that your class scored the following grades on the first exam in this class:
75, 90, 81, 83, 62, 45, 98, 65, 77, 72, 80, 88, 76, 56, 75, 83, 67, 82, 91, 86, 84, 86, 97, 72, 71
Create a stem plot and make a conjecture about the meaning of the data. State the center, spread, and
the shape. Does an outlier exist? What does it mean?
2. This data set gives pulse rates, in beats per minute, for a group of 30 students.
72 56 88 76 80 68 80 84 64 80 72 64 68 76 72
68 60 76 68 64 80 72 76 92 68 56 72 68 60 84
Create a dotplot for this information, naming the center, shape, and spread. What does the data tell us?
3. This table shows the heights of the ten tallest mountains in the world.
Mountain Heights
Construct an appropriate graphical representation of this data. Interpret the data.
4. The students in one social studies class were asked how many brothers and sisters (siblings) they each
have. The dot plot here shows the results.
a. How many of the students have six siblings?
b. How many of the students have no siblings?
c. How many of the students have three or more siblings?
Essential Statistics
Dotplots & Stemplots
Name:_____________________________
5. In June 2004, 16 gas stations in Ithaca, NY, posted these prices for a gallon of regular gasoline.
2.029
2.119
2.259
2.049
2.079
2.089
2.079
2.039
2.069
2.269
2.099
2.129
2.169
2.189
2.039
2.079
a. Make a stem-plot display of these gas prices. Use the following split stems: use 2.1 for prices
between $2.10 and $2.149, etc.
b. Describe the shape, center, and spread of this distribution.
c. What unusual feature do you see?
6. The data below gives the number of hurricanes that happened each year from 1944 through 2000 as
reported by Science magazine.
3, 2, 1, 3, 4, 3, 7, 2, 3, 3, 2, 5, 2, 2, 4, 2, 2, 6, 0, 2, 5, 1, 3, 1, 0, 3, 2, 1, 0, 1, 2, 3, 2, 1,
2, 2, 2, 3, 1, 1, 1, 3, 0, 1, 3, 2, 1, 2, 1, 1, 0, 5, 6, 1, 3, 5, 3
Create a dot plot, and describe the distribution.