Finding the Fourth Proportional to 1,439.61, 1,986.55 and 810.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.61 : 1,986.55 = 810.06 : x
2. Step 2: Convert to fraction form
   1,439.61/1,986.55 = 810.06/x
3. Step 3: Cross multiply
   1,439.61x = 1,986.55 × 810.06
4. Step 4: Simplify right side
   1,439.61x = 1,609,224.69
5. Step 5: Solve for x
   x = 1,609,224.69/1,439.61
6. Step 6: Final answer
   x = 1,117.82