Question

The following are marks in a class assessment:

4, 6, 7, 5, 3, 5, 4, 5, 2, 6, 2, 5, 1, 9, 6, 5, 8, 4, 6, 7

Draw the Tally mark - frequency table and find the arithmetic mean.

Answer 1

(2 marks)

Arithmetic mean = $\frac{Sumofallobservations}{Totalnumberofobservation}$

(0.5 mark)

Then,

Sum of all observation
= 1 + 2 + 2 + 3 + 4 + 4 + 4 + 5 + 5 + 5 + 5 + 5 + 6 + 6 + 6 + 6 + 7 + 7 + 8 + 9
= 100

Total number of observation = 20

(0.5 mark)

⇒ Arithmetic mean = $\frac{100}{20}$ = 5

(1 mark)