Finding the Fourth Proportional to 1,345.96, 2,019.55 and 687.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.96 : 2,019.55 = 687.43 : x
2. Step 2: Convert to fraction form
   1,345.96/2,019.55 = 687.43/x
3. Step 3: Cross multiply
   1,345.96x = 2,019.55 × 687.43
4. Step 4: Simplify right side
   1,345.96x = 1,388,292.49
5. Step 5: Solve for x
   x = 1,388,292.49/1,345.96
6. Step 6: Final answer
   x = 1,031.45