Texting and Teens
Did you know:
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During 2008, Americans sent a total of 880 billion text messages! ( CL King and Associates )
Using the Census Bureau’s estimated population of 306 million people in the United States, this statistic
indicates that, on average, EVERY, man, woman, and child sent 2,876 text messages a year, regardless of
whether or not they have a cell phone!
In more simplified terms, this means EVERY person in the country sends 240 text messages a month or 8 text
messages a day!
Mission:
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The school conducted a survey of 31 seventh grade students – 16 girls and 15 boys – asking them “How many
text messages did you send yesterday?”. The results are shown below.
Create a visual representation ( double box-and-whisker plot ) of the data that compares the number of text
messages sent by girls to the number of text messages sent by boys.
Number of Text Messages Sent by Girls:
84
57
64
71
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86
175
19
49
73
81
51
27
122
40
39
114
29
116
14
6
18
25
21
Number of Text Messages Sent by Boys:
35
24
42
63
18
71
23
38
Process:
15 points
1. Calculate the five-number summaries for each data set- the number of text messages sent by girls and the
number of text messages sent by boys.
Lower Extreme Lower Quartile Median
Upper Quartile Upper Extreme
st
nd
(1 )
Quartile ( 2 ) ( 3rd )
Text Messages
by Girls
Text Messages
by Boys
20 points
2. Construct a double box-and-whisker plot. ( Plot the data for each data set using the same horizontal axis. )
# of Text Messages by Girls
# of Text Messages by Boys
2 points each
3.
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Analyze the data and answer the following questions
What is the minimum number of texts that were sent amongst all students surveyed? _____________
What is the maximum number of texts that were sent amongst all students surveyed? ____________
If Emily sent the least tests, how many texts did she send?
______________
If Thomas sent the most texts, how many texts did he send?
_____________
What is the measure of variation, or range, for the number of text messages sent by girls? ____________
What is the measure of variation, or range, for the number of text messages sent by boys? ____________
Which measure of center can be easily identified from the box-and-whisker plot?
________________
What is the median number of text messages sent by girls?
_____________
What is the median number of text messages sent by boys?
_____________
What percent of the text messages make up the inter-quartile range?
_____________
Why is the inter-quartile range significant? __________________________________________________
_____________________________________________________________________________________
What is the inter-quartile range for the number of texts sent by girls?
_____________
What is the inter-quartile range for the number of texts sent by boys?
_____________
What percent of the text messages are between the lower extreme and the lower quartile? ___________
What percent of the text messages are between the upper extreme and the upper quartile? ___________
Altogether, the length of the whole box-and-whisker, from one tip of a whisker to the other, represents what
percent of the data set?
______________
What can you conclude about texting? Who sends the most texts, girls or boys? Explain your answer.
___________________________________________________________________________________________
___________________________________________________________________________________________
4. Add your own data and describe what happens to the measures of center.
 Calculate how many texts you send in ONE day. Record that here.
________________
 How does including your number of texts change the mean? ( increase/decrease) by how
much?_____________________________________________________________________________________
 How does including your number of texts change the median? ( increase/decrease) how
much?_____________________________________________________________________________________