If we observe the graph carefully, we realize that the data has been misinterpreted.
As we know areas of the rectangle should be proportional to the frequencies in a histogram. Now look at the chart below.
If we go by the rules we realize that there is an ! ERROR ! in the first and the last class interval.
We take the following steps to rectify the error
1.We select an approriate class size. The best suitable would be 10.
2.The lengths of the rectangle are then modified to be proportionate to the class size.
Directions: On the basis of the given information answer the following questions