Finding the Fourth Proportional to 402,688.72, 604,499.70 and 216,064.72

Step by Step Solution

1. Step 1: Write the proportion equation
   402,688.72 : 604,499.70 = 216,064.72 : x
2. Step 2: Convert to fraction form
   402,688.72/604,499.70 = 216,064.72/x
3. Step 3: Cross multiply
   402,688.72x = 604,499.70 × 216,064.72
4. Step 4: Simplify right side
   402,688.72x = 130,611,058,420.58
5. Step 5: Solve for x
   x = 130,611,058,420.58/402,688.72
6. Step 6: Final answer
   x = 324,347.45