Step 1: Understand the formula for mean of discrete frequency distribution

The mean of a discrete frequency distribution is given by the formula where we divide the sum of the product of each observation and its frequency by the total frequency: $\overline{x} = \frac{\sum f_i x_i}{\sum f_i}$

$\overline{x} = \frac{\sum f_i x_i}{\sum f_i}$

Step 2: Calculate products of marks and number of students ($f_i x_i$)

Multiply each mark $x_i$ with its corresponding frequency $f_i$:

• $25 \times 5 = 125$
• $30 \times 6 = 180$
• $35 \times 3 = 105$
• $40 \times 1 = 40$

$\sum f_i x_i = 125 + 180 + 105 + 40 = 450$

Step 3: Calculate the total number of students ($\sum f_i$)

Sum up all the individual frequencies to get the total number