Finding the Fourth Proportional to 645,463, 890,733.98 and 355,068.30

Step by Step Solution

1. Step 1: Write the proportion equation
   645,463 : 890,733.98 = 355,068.30 : x
2. Step 2: Convert to fraction form
   645,463/890,733.98 = 355,068.30/x
3. Step 3: Cross multiply
   645,463x = 890,733.98 × 355,068.30
4. Step 4: Simplify right side
   645,463x = 316,271,400,030.83
5. Step 5: Solve for x
   x = 316,271,400,030.83/645,463
6. Step 6: Final answer
   x = 489,991.53