Finding the Fourth Proportional to 1,007.52, 1,389.76 and 614.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.52 : 1,389.76 = 614.40 : x
2. Step 2: Convert to fraction form
   1,007.52/1,389.76 = 614.40/x
3. Step 3: Cross multiply
   1,007.52x = 1,389.76 × 614.40
4. Step 4: Simplify right side
   1,007.52x = 853,868.54
5. Step 5: Solve for x
   x = 853,868.54/1,007.52
6. Step 6: Final answer
   x = 847.50