Finding the Fourth Proportional to 525,860, 725,686.80 and 299,636.72

Step by Step Solution

1. Step 1: Write the proportion equation
   525,860 : 725,686.80 = 299,636.72 : x
2. Step 2: Convert to fraction form
   525,860/725,686.80 = 299,636.72/x
3. Step 3: Cross multiply
   525,860x = 725,686.80 × 299,636.72
4. Step 4: Simplify right side
   525,860x = 217,442,412,499.30
5. Step 5: Solve for x
   x = 217,442,412,499.30/525,860
6. Step 6: Final answer
   x = 413,498.67