Finding the Fourth Proportional to 1,288.06, 1,777.53 and 698.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.06 : 1,777.53 = 698.60 : x
2. Step 2: Convert to fraction form
   1,288.06/1,777.53 = 698.60/x
3. Step 3: Cross multiply
   1,288.06x = 1,777.53 × 698.60
4. Step 4: Simplify right side
   1,288.06x = 1,241,789.52
5. Step 5: Solve for x
   x = 1,241,789.52/1,288.06
6. Step 6: Final answer
   x = 964.08