1. The table shows the speed of some cars.
   Work out the frequency density of the class $5 < s \le 15$.

   Speed, s (mph)	Frequency
   0 < s ≤ 5	5
   5 < s ≤ 15	25
   15 < s ≤ 25	15
   25 < s ≤ 30	20
   30 < s ≤ 40	30

2. The histogram shows the time of some runners.
   Estimate the total number of runners.
3. The histogram shows the height of 100 plants.
   Estimate the percentage of plants with a height of more than 20 cm, by taking half of the 10–30 bar.

1. The table shows the speed of some cars.
   Work out the frequency density of the class $5 < s \le 15$.

   Speed, s (mph)	Frequency
   0 < s ≤ 5	5
   5 < s ≤ 15	25
   15 < s ≤ 25	15
   25 < s ≤ 30	20
   30 < s ≤ 40	30

2. The histogram shows the time of some runners.
   Estimate the total number of runners.
3. The histogram shows the height of 100 plants.
   Estimate the percentage of plants with a height of more than 20 cm, by taking half of the 10–30 bar.

1. The table shows the speed of some cars.
   Work out the frequency density of the class $5 < s \le 15$.

   Speed, s (mph)	Frequency
   0 < s ≤ 5	5
   5 < s ≤ 15	25
   15 < s ≤ 25	15
   25 < s ≤ 30	20
   30 < s ≤ 40	30

2. The histogram shows the time of some runners.
   Estimate the total number of runners.
3. The histogram shows the height of 100 plants.
   Estimate the percentage of plants with a height of more than 20 cm, by taking half of the 10–30 bar.

1. The table shows the speed of some cars.
   Work out the frequency density of the class $5 < s \le 15$.

   Speed, s (mph)	Frequency
   0 < s ≤ 5	5
   5 < s ≤ 15	25
   15 < s ≤ 25	15
   25 < s ≤ 30	20
   30 < s ≤ 40	30

2. The histogram shows the time of some runners.
   Estimate the total number of runners.
3. The histogram shows the height of 100 plants.
   Estimate the percentage of plants with a height of more than 20 cm, by taking half of the 10–30 bar.