Finding the Fourth Proportional to 100.98, 139.31 and 61.62

Step by Step Solution

1. Step 1: Write the proportion equation
   100.98 : 139.31 = 61.62 : x
2. Step 2: Convert to fraction form
   100.98/139.31 = 61.62/x
3. Step 3: Cross multiply
   100.98x = 139.31 × 61.62
4. Step 4: Simplify right side
   100.98x = 8,584.28
5. Step 5: Solve for x
   x = 8,584.28/100.98
6. Step 6: Final answer
   x = 85.01