Page 27 - 2024-bfw-starnes-TPS7e-SE proofs.indd

14 UNIT 1 Exploring One-Variable Data

SOLUTION:
Tweens tend to report less daily screen time than teens. Tweens are more likely than teens to spend no time
(6% versus 3%), less than 2 hours (24% versus 7%), and from 2 to less than 4 hours (23% versus 15%) on
digital devices per day. Teens are more likely than tweens to spend from 4 to less than 8 hours (34% versus
© 2024 BFW Publishers PAGES NOT FINAL - For Review Purposes Only - Do Not Copy
27%) and 8 or more hours (41% versus 20%) on digital devices per day. More than half (53%) of tweens report
less than 4 hours of screen time per day, while 75% of teens report 4 or more hours per day of screen time.

FoR PRAcTIce, TRY eXeRcISe 7

The following relative frequency table summarizes the data on daily screen
time from the example by age group. As a result, the percentages in each row
add to 100%. Note that we could have also compared the distributions with this
relative frequency table.
Daily time spent on digital devices
None < 2 hours 2 to < 4 hours 4 to < 8 hours 8+ hours
Teens 3% 7% 15% 34% 41%
Age group
Tweens 6% 24% 23% 27% 20%

In the example, we grouped the bars by age group in the side-by-side bar graph.
This arrangement clearly shows the two distributions of daily screen time — one
for the teens and one for the tweens in the sample. It is also possible to group
the bars by daily screen time, as in the following graph. This arrangement makes
category-by-category comparisons for the daily time spent on digital devices
easier — but now it’s harder to see the individual distributions of daily screen time
for the teens and for the tweens. Whichever way you organize the bars, be sure to
include a key that describes what each color or type of shading on the side-by-side
bar graph represents.

45
40
35
30
Percent 25
20
Age group
15
Teens
10 Tweens
5
0
None <2 2 to <4 4 to <8 8+
Daily screen time (h)

Misleading Graphs

Bar graphs can be a bit dull to look at. It is tempting to replace the bars with pic-
tures or to use special three-dimensional (3D) effects to make the graphs seem
more interesting. Don’t do it! Our eyes react to the area of the bars as well as to

© 2024 BFW Publishers PAGES NOT FINAL - For Review Purposes Only, all other uses prohibited - Do Not Copy or Post in Any Form.

02_StarnesTPS7e_40934_un01_p1_001_086_6pp.indd 14 13/09/23 5:36 PM