These histograms graph the amount of time (hours per day) that 46 middle school girls and 40 middle school boys in San Francisco spend on the website FaceSpace. 50 boys and 50 girls took the survey but 4 girls and 10 boys did not use these sites at all. Each is graphed with a bin width of 0.25 hours.
Answer
Example 2
How many boys spend more than 1.5 hours/day on social networking sites?
Hint
add up the last two bars
Answer
8
Example 3
Compare the percentage of boys and girls that spend more than zero but less than 1 hour/day on these sites.
Hint
divide the girls by 46 and the boys by 40
Answer
about 50% of boys and about 22% of girls spend less than 1 hour/day
Example 4
Find the interval where the median of the boys' data set lies
Hint
the median will be between the 20th and 21st value
Answer
0.75 – 1 hour/day
Example 5
What can you conclude based on these graphs?
Hint
What does this make you think about the difference between girls and boys on social networking sites? (These answers will vary, so put on your mega-brain hats and come up with a conclusion in your own words.)
Answer
Girls spend much more time on these sites than boys. In addition, their times vary more widely, ranging from zero to 4 hours/day, while the boys' times top out at 2 hours/day.
