The following are the amounts (to the nearest dollar)
paid by 25 students for textbooks during the fall term:
a. Draw an ordered stem and leaf plot to illustrate the
data.
b. Construct a grouped frequency table for the data,
starting the first class at $15.00 with intervals of
$5.00 each.
c. Draw a bar graph of the data.
45 37 62 30 23
48 41 49 62 40
33 39 23 53 51
42 50 16 58 39
35 42 37 60 50
http://www.wisc-online.com/objects/ViewObject.aspx?ID=TMH1101
Use the info for that plot to get intervals $15-19, $20-24, and so on to get your information for a bar graph.
a. To draw an ordered stem and leaf plot, you need to separate each number into a stem and a leaf. The stem represents the tens place of the number, and the leaf represents the ones place of the number.
First, sort the numbers in ascending order:
16, 23, 23, 30, 33, 35, 37, 37, 39, 39, 40, 41, 42, 42, 45, 48, 49, 50, 50, 51, 53, 58, 60, 62, 62
Next, create the stem column by listing the tens place of each number:
1, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6
Now, create the leaf column by listing the ones place of each number:
6, 3, 3, 0, 3, 5, 7, 7, 9, 9, 0, 1, 2, 2, 5, 8, 9, 0, 0, 1, 3, 8, 0, 2, 2
Lastly, combine the stem and leaf columns to form the stem and leaf plot:
1 | 6
2 | 3 3 0
3 | 3 5 7 7 9 9
4 | 0 1 2 2 5 8 9
5 | 0 0 1 3 8
6 | 0 2 2
b. To construct a grouped frequency table, you will group the data into intervals. Starting with $15.00 as the first class, we can create intervals of $5.00 each.
The intervals and their respective frequencies are as follows:
$15 - $19: 1
$20 - $24: 2
$25 - $29: 2
$30 - $34: 4
$35 - $39: 3
$40 - $44: 3
$45 - $49: 3
$50 - $54: 4
$55 - $59: 1
$60 - $64: 2
c. To draw a bar graph of the data, you will use the grouped frequency table created in part b.
On the horizontal axis, label the intervals from part b. On the vertical axis, label the frequency of each interval.
Create rectangular bars for each interval, with the height of each bar representing the frequency.
Use the scale on the vertical axis to determine the height of each bar.
Count the frequency for each interval and draw a bar above the corresponding interval on the horizontal axis, making sure the height of the bar reflects the frequency. Repeat this for all the intervals.
For example, above the interval $30 - $34, you would draw a bar with a height of 4 since the frequency for that interval is 4. Repeat this process for all other intervals.
Once all the bars are drawn, label the vertical axis as "Frequency" and the horizontal axis as "Textbook Costs."