Finding the Fourth Proportional to 72,488.80, 109,024.80 and 64,907.20

Step by Step Solution

1. Step 1: Write the proportion equation
   72,488.80 : 109,024.80 = 64,907.20 : x
2. Step 2: Convert to fraction form
   72,488.80/109,024.80 = 64,907.20/x
3. Step 3: Cross multiply
   72,488.80x = 109,024.80 × 64,907.20
4. Step 4: Simplify right side
   72,488.80x = 7,076,494,498.56
5. Step 5: Solve for x
   x = 7,076,494,498.56/72,488.80
6. Step 6: Final answer
   x = 97,621.90