(i) The number of athletes who ran between 10.5 and 11.0 seconds is the difference in cumulative frequencies:

\(10 - 4 = 6.\)

(ii) To draw the histogram, calculate the frequency for each interval:

• 10.0 to 10.5: 4 athletes
• 10.5 to 11.0: 6 athletes
• 11.0 to 12.0: 30 athletes
• 12.0 to 12.5: 9 athletes
• 12.5 to 13.5: 8 athletes

Use these frequencies to draw the histogram with appropriate widths and heights.

(iii) Calculate the mean using midpoints:

\(E(X) = \frac{(10.25 \times 4) + (10.75 \times 6) + (11.5 \times 30) + (12.25 \times 9) + (13 \times 8)}{57} = 11.7\)

Calculate the variance:

\(\text{Var}(X) = \frac{(10.25^2 \times 4) + (10.75^2 \times 6) + (11.5^2 \times 30) + (12.25^2 \times 9) + (13^2 \times 8)}{57} - (11.7)^2 = 0.547\)