Problem 6
A histogram shows the number of hours students spent preparing for a test. The table below gives the intervals and the heights of the bars (in percent per hour). Intervals contain the left endpoint but not the right. No student spent 25 hours or more in preparation.
time (hours) height
0-4 2.5
4-10 6
10-15 ?
15-25 1
: 2.0 points
What percent of students spent fewer than 4 hours in preparation?
3 students
To find the percent of students who spent fewer than 4 hours in preparation, you need to add up the heights of the bars from 0 to 4 hours.
According to the table, the height of the bar for 0-4 hours is 2.5 percent per hour.
So, the percent of students who spent fewer than 4 hours in preparation is 2.5%.
To find the percent of students who spent fewer than 4 hours in preparation, we can look at the height of the bar in the interval 0-4. According to the table, the height in this interval is 2.5 percent per hour.
To find the percent of students, we need to add up the heights of all the bars before the interval 0-4.
In this case, there are no bars before the interval 0-4, so the percent of students who spent fewer than 4 hours in preparation is simply 2.5 percent.
Therefore, the answer is 2.5 percent of students spent fewer than 4 hours in preparation.