Question on: JAMB Mathematics - 2023

To estimate the mean, we need to find the sum of the products of the class marks and frequencies, and then divide by the sum of frequencies.

\[ \text{Class Interval} \quad | \quad \text{Class Mark} \quad | \quad \text{Frequency (f)} \quad | \quad fx \]
\[ \text{5 - 6} \quad | \quad 5.5 \quad | \quad 29 \quad | \quad 5.5 \times 29 = 159.5 \]
\[ \text{7 - 8} \quad | \quad 7.5 \quad | \quad 40 \quad | \quad 7.5 \times 40 = 300 \]
\[ \text{9 - 10} \quad | \quad 9.5 \quad | \quad 38 \quad | \quad 9.5 \times 38 = 361 \]
\[ \sum f = 107 \quad | \quad \sum fx = 820.5 \]

Now, calculate the mean:

\[ \text{Mean} = \frac{\sum fx}{\sum f} = \frac{820.5}{107} \approx 7.663 \]

Rounded to one decimal place, the mean is approximately 7.7.

Therefore, the correct answer is 7.7.