Finding the Fourth Proportional to 644,499.55, 889,410.72 and 358,019.86

Step by Step Solution

1. Step 1: Write the proportion equation
   644,499.55 : 889,410.72 = 358,019.86 : x
2. Step 2: Convert to fraction form
   644,499.55/889,410.72 = 358,019.86/x
3. Step 3: Cross multiply
   644,499.55x = 889,410.72 × 358,019.86
4. Step 4: Simplify right side
   644,499.55x = 318,426,701,456.90
5. Step 5: Solve for x
   x = 318,426,701,456.90/644,499.55
6. Step 6: Final answer
   x = 494,068.15