In a survey of people who grew tomatoes, they were asked to give the height of their largest tomato plant in centimetres. The data is as follows:

[0, 10) 2 people

[10, 20) 6 people

[20, 30) 12 people

[30, 40) 8 people

[40 50) 4 people

a) Make a relative frequency distribution table of the sizes of plants.

b) Make a cumulative relative frequency distribution table of the sizes of plants.

c) Make a histogram of the data.