Finding the Fourth Proportional to 1,007.96, 1,509.18 and 763.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.96 : 1,509.18 = 763.78 : x
2. Step 2: Convert to fraction form
   1,007.96/1,509.18 = 763.78/x
3. Step 3: Cross multiply
   1,007.96x = 1,509.18 × 763.78
4. Step 4: Simplify right side
   1,007.96x = 1,152,681.50
5. Step 5: Solve for x
   x = 1,152,681.50/1,007.96
6. Step 6: Final answer
   x = 1,143.58