(i) The modal age group is the one with the highest frequency density. From the histogram, the age group 30-35 years has the highest frequency density.

(ii) To find the number of fathers between 25 and 30 years old, multiply the frequency density by the class width. The frequency density for 25-30 years is 4.8, and the class width is 5 years. Therefore, the number of fathers is:

\(4.8 \times 5 = 24\)

(iii) To find the total number of fathers in the sample, sum the frequencies for all age groups. The frequencies are calculated by multiplying the frequency density by the class width for each group:

\(4 \times 1 + 3.6 \times 5 + 4.8 \times 5 + 5.6 \times 5 + 5.2 \times 5 + 2 \times 5 = 4 + 18 + 24 + 28 + 26 + 10 = 110\)