Step 1: Find the minimum and maximum values.
Minimum:   Maximum:

Step 2: Round the minimum down to the nearest 10.
Range Minimum:

Step 3: Round the maximum up to the nearest 10.
Range Maximum:

Step 4: Calculate the range.
Range: 90 - 20 =

Step 5: Find the size of each interval by dividing the range by the number of intervals.
70 / 5 =

Step 6: The intervals are calculated by starting at the minimum and adding the interval size:
      20 + 14 = 34.
Each interval is found by adding 14 to the end of the previous interval.

Step 7: Create the bars of the histogram by dragging each number to its appropriate location on the horizontal axis.