Finding the Fourth Proportional to 1,287.50, 1,776.76 and 698.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.50 : 1,776.76 = 698.04 : x
2. Step 2: Convert to fraction form
   1,287.50/1,776.76 = 698.04/x
3. Step 3: Cross multiply
   1,287.50x = 1,776.76 × 698.04
4. Step 4: Simplify right side
   1,287.50x = 1,240,247.81
5. Step 5: Solve for x
   x = 1,240,247.81/1,287.50
6. Step 6: Final answer
   x = 963.30