The interval of 0-19 will increase by 20 of either Hay Bale Toss or Pie Eating Contest.
Step-by-step explanation:
Number of students visiting the fair = 20
Age group = 0-16
In the histogram, this age group falls in the first interval which is 0-19.
If all 20 students joined the Hay Bale Toss then the bar of 0-19 of Hay Bale Toss will increase from 40 to 60 and the graph of Pie Eating Contest will remain the same.
If all 20 students joined the Pie Eating Contest then the bar of 0-19 of Hay Bale Toss will increase from 20 to 40 and the graph of Hay Bale Toss will remain the same.
<em>Therefore, only one if the graph's interval of 0-19 will increase by 20 whereas the other graph would remain the same.</em>