Finding the Fourth Proportional to 100.91, 139.29 and 62.10

Step by Step Solution

1. Step 1: Write the proportion equation
   100.91 : 139.29 = 62.10 : x
2. Step 2: Convert to fraction form
   100.91/139.29 = 62.10/x
3. Step 3: Cross multiply
   100.91x = 139.29 × 62.10
4. Step 4: Simplify right side
   100.91x = 8,649.91
5. Step 5: Solve for x
   x = 8,649.91/100.91
6. Step 6: Final answer
   x = 85.72