Question:
Find the mean, median and mode of the following data:
Solution:
Consider the following data.
Here, the maximum frequency is 12 so the modal class is 60−80.
Therefore,
$l=60$
$h=20$
$f=12$
$f_{1}=10$
$f_{2}=6$
$F=24$
Median $=l+\frac{\frac{N}{2}-F}{f} \times h$
$=60+\frac{25-24}{12} \times 20$
$=60+\frac{1}{12} \times 20$
Median $=61.66$
Thus, the median of the data is 61.66.
Mean $=\frac{\sum f_{i} x_{i}}{\sum f}$
$=\frac{3120}{50}$
Mean = 62.4
Thus, the mean of the data is 62.4.
Mode
$=l+\frac{f-f_{1}}{2 f-f_{1}-f_{2}} \times h$
$=60+\frac{12-10}{24-10-6} \times 20$
$=60+\frac{2}{8} \times 20$
Mode $=65$
Thus, the mode of the data is 65.