Question

Find the mean of the following data.

$$\begin{array}{cccccccc}NumberofPlants& 0-2& 2-4& 4-6& 6-8& 8-10& 10-12& 12-14\\ NumberofHouses& 1& 3& 2& 4& 5& 3& 2\end{array}$$

• A. 7.6
• B. 15.2
• C. 3.8
• D. 10

Answer 1

The correct option is A 7.6

$$\begin{array}{ccc}\text{Class Mark}& \text{Number of Houses}& fx\\ \text{1}& \text{1}& \text{1}\\ \text{3}& \text{3}& \text{9}\\ \text{5}& \text{2}& \text{10}\\ \text{7}& \text{4}& \text{28}\\ \text{9}& \text{5}& \text{45}\\ \text{11}& \text{3}& \text{33}\\ \text{13}& \text{2}& \text{26}\end{array}$$
$N$=20
$\sum fx$ = 152
Note that $\overline{x}$ = $\frac{\sum fx}{N}$,
where $\overline{x}$ stands for mean and $N$ stands for the sum of frequencies.
$⟹Mean=\frac{152}{20}=7.6$