Finding the Fourth Proportional to 1,089.63, 1,502.69 and 810.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,089.63 : 1,502.69 = 810.56 : x
2. Step 2: Convert to fraction form
   1,089.63/1,502.69 = 810.56/x
3. Step 3: Cross multiply
   1,089.63x = 1,502.69 × 810.56
4. Step 4: Simplify right side
   1,089.63x = 1,218,020.41
5. Step 5: Solve for x
   x = 1,218,020.41/1,089.63
6. Step 6: Final answer
   x = 1,117.83