Finding the Fourth Proportional to 402,726.89, 555,748.88 and 221,437.55

Step by Step Solution

1. Step 1: Write the proportion equation
   402,726.89 : 555,748.88 = 221,437.55 : x
2. Step 2: Convert to fraction form
   402,726.89/555,748.88 = 221,437.55/x
3. Step 3: Cross multiply
   402,726.89x = 555,748.88 × 221,437.55
4. Step 4: Simplify right side
   402,726.89x = 123,063,666,516.51
5. Step 5: Solve for x
   x = 123,063,666,516.51/402,726.89
6. Step 6: Final answer
   x = 305,575.99