Finding the Fourth Proportional to 100,315, 138,434.72 and 55,603

Step by Step Solution

1. Step 1: Write the proportion equation
   100,315 : 138,434.72 = 55,603 : x
2. Step 2: Convert to fraction form
   100,315/138,434.72 = 55,603/x
3. Step 3: Cross multiply
   100,315x = 138,434.72 × 55,603
4. Step 4: Simplify right side
   100,315x = 7,697,385,736.16
5. Step 5: Solve for x
   x = 7,697,385,736.16/100,315
6. Step 6: Final answer
   x = 76,732.15