Finding the Fourth Proportional to 73,172, 100,978.08 and 39,638.72

Step by Step Solution

1. Step 1: Write the proportion equation
   73,172 : 100,978.08 = 39,638.72 : x
2. Step 2: Convert to fraction form
   73,172/100,978.08 = 39,638.72/x
3. Step 3: Cross multiply
   73,172x = 100,978.08 × 39,638.72
4. Step 4: Simplify right side
   73,172x = 4,002,641,839.26
5. Step 5: Solve for x
   x = 4,002,641,839.26/73,172
6. Step 6: Final answer
   x = 54,701.82