Finding the Fourth Proportional to 1,042.06, 1,561.63 and 809.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,042.06 : 1,561.63 = 809.89 : x
2. Step 2: Convert to fraction form
   1,042.06/1,561.63 = 809.89/x
3. Step 3: Cross multiply
   1,042.06x = 1,561.63 × 809.89
4. Step 4: Simplify right side
   1,042.06x = 1,264,748.52
5. Step 5: Solve for x
   x = 1,264,748.52/1,042.06
6. Step 6: Final answer
   x = 1,213.70