Question

calculate the mean of the following distribution using direct method
class interval:0-10,10-20,20-30,30-40,40-50
frequency:5,7,15,28,8 ​

Answer 1

Answer:

$\frac{5 \times 5 + 7 \times 15 + 15 \times 25 + 28 \times 35 + 8 \times 45}{5 + 7 + 15 + 28 + 8}$

$\frac{25 + 105 + 375 + 980 + 360}{63} = \frac{1845}{63} = 29.28$