Finding the Fourth Proportional to 1,189,494.72, 1,641,458.72 and 645,618.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189,494.72 : 1,641,458.72 = 645,618.80 : x
2. Step 2: Convert to fraction form
   1,189,494.72/1,641,458.72 = 645,618.80/x
3. Step 3: Cross multiply
   1,189,494.72x = 1,641,458.72 × 645,618.80
4. Step 4: Simplify right side
   1,189,494.72x = 1,059,756,614,773.63
5. Step 5: Solve for x
   x = 1,059,756,614,773.63/1,189,494.72
6. Step 6: Final answer
   x = 890,930.07