Finding the Fourth Proportional to 659,385.50, 988,998.03 and 280,458.59

Step by Step Solution

1. Step 1: Write the proportion equation
   659,385.50 : 988,998.03 = 280,458.59 : x
2. Step 2: Convert to fraction form
   659,385.50/988,998.03 = 280,458.59/x
3. Step 3: Cross multiply
   659,385.50x = 988,998.03 × 280,458.59
4. Step 4: Simplify right side
   659,385.50x = 277,372,988,061.59
5. Step 5: Solve for x
   x = 277,372,988,061.59/659,385.50
6. Step 6: Final answer
   x = 420,653.76