Finding the Fourth Proportional to 1,189,526.72, 1,641,510.24 and 645,636.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189,526.72 : 1,641,510.24 = 645,636.80 : x
2. Step 2: Convert to fraction form
   1,189,526.72/1,641,510.24 = 645,636.80/x
3. Step 3: Cross multiply
   1,189,526.72x = 1,641,510.24 × 645,636.80
4. Step 4: Simplify right side
   1,189,526.72x = 1,059,819,418,520.83
5. Step 5: Solve for x
   x = 1,059,819,418,520.83/1,189,526.72
6. Step 6: Final answer
   x = 890,958.90