Use the ratio to find the number of units, then find the father's mass.<br><br>
[[model:questions/solutions/q4637.png]]<br><br>
&bull; Total units = 8 + 11 = 19 units<br>
&bull; 19 units = 134.9 kg<br>
&bull; 1 unit = 134.9 ÷ 19 = 7.1 kg<br>
&bull; Father's mass = 11 units = 11 × 7.1 = 78.1 kg<br>
<br>
Jake's father weighs 78.1 kg.<br>
Check: Jake = 8 × 7.1 = 56.8 kg. 56.8 + 78.1 = 134.9. ✓