Finding the Fourth Proportional to 1,392.72, 2,087.10 and 698.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.72 : 2,087.10 = 698.73 : x
2. Step 2: Convert to fraction form
   1,392.72/2,087.10 = 698.73/x
3. Step 3: Cross multiply
   1,392.72x = 2,087.10 × 698.73
4. Step 4: Simplify right side
   1,392.72x = 1,458,319.38
5. Step 5: Solve for x
   x = 1,458,319.38/1,392.72
6. Step 6: Final answer
   x = 1,047.10