Finding the Fourth Proportional to 1,287.30, 1,776.72 and 763.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.30 : 1,776.72 = 763.62 : x
2. Step 2: Convert to fraction form
   1,287.30/1,776.72 = 763.62/x
3. Step 3: Cross multiply
   1,287.30x = 1,776.72 × 763.62
4. Step 4: Simplify right side
   1,287.30x = 1,356,738.93
5. Step 5: Solve for x
   x = 1,356,738.93/1,287.30
6. Step 6: Final answer
   x = 1,053.94