Sured to the nearest
24. The heights of some plants in a nursery were measured to the ne
centimetre and the results recorded in the table below.
Height (cm) / 5-9 10-14 15-19 20-24 25–29 30–34 | 35–39 40-44 Tas
No of plants 4 9 15 20 30 12 5 3
By modifying the table
(a) Use the method of assumed mean to calculate the actual mean
| height of the plants.
(b) Calculate to one deccimal place the standard deviation of the
distribution.
(4 mark
(6 mar