Finding the Fourth Proportional to 100.86, 139.15 and 59.43

Step by Step Solution

1. Step 1: Write the proportion equation
   100.86 : 139.15 = 59.43 : x
2. Step 2: Convert to fraction form
   100.86/139.15 = 59.43/x
3. Step 3: Cross multiply
   100.86x = 139.15 × 59.43
4. Step 4: Simplify right side
   100.86x = 8,269.14
5. Step 5: Solve for x
   x = 8,269.14/100.86
6. Step 6: Final answer
   x = 81.99