1

A histogram is to be drawn for this data. Work out the height (frequency density) of the bar for the class $20 < t \le 30$.

[2]

2

The histogram shows the time of some runners. Estimate how many had a time between 35 and 60 min. [3]

3

A histogram is to be drawn for this data. Work out the height (frequency density) of the bar for the class $40 < w \le 50$.

[2]

4

The histogram shows the time of some runners. Estimate how many had a time between 10 and 25 min. [3]