Finding the Fourth Proportional to 1,390.96, 2,086.72 and 698.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.96 : 2,086.72 = 698.08 : x
2. Step 2: Convert to fraction form
   1,390.96/2,086.72 = 698.08/x
3. Step 3: Cross multiply
   1,390.96x = 2,086.72 × 698.08
4. Step 4: Simplify right side
   1,390.96x = 1,456,697.50
5. Step 5: Solve for x
   x = 1,456,697.50/1,390.96
6. Step 6: Final answer
   x = 1,047.26