Finding the Fourth Proportional to 1,287.52, 1,776.78 and 698.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.52 : 1,776.78 = 698.06 : x
2. Step 2: Convert to fraction form
   1,287.52/1,776.78 = 698.06/x
3. Step 3: Cross multiply
   1,287.52x = 1,776.78 × 698.06
4. Step 4: Simplify right side
   1,287.52x = 1,240,290.16
5. Step 5: Solve for x
   x = 1,240,290.16/1,287.52
6. Step 6: Final answer
   x = 963.32