The histogram shows the number of hours volunteers worked one week. what percent of the volunteers worked 8 to 11 hours or 16 to 19 hours? enter your answer in the box.

To determine the percent volunteers that worked in the intervals mentioned, you will need to create a ratio of the number of volunteers who worked in those 2 bars to the total number of volunteers in all the bars.  The number in those 2 intervals are 4+5=9,  The total number of volunteer represented in the histogram is 20.  This creates a fraction 9/20.  TO convert this to a percent, you can create an equivalent fraction with a denominator of 100 by multiplying by 5.  This means the 9 is also multiplied by 5 to make 45/100.  This is equivalent to 45%.  You can also divide 9 and 20 to get 0.45 (45%).

Ithink the answer is c