Finding the Fourth Proportional to 1,287.45, 1,776.71 and 763.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.45 : 1,776.71 = 763.48 : x
2. Step 2: Convert to fraction form
   1,287.45/1,776.71 = 763.48/x
3. Step 3: Cross multiply
   1,287.45x = 1,776.71 × 763.48
4. Step 4: Simplify right side
   1,287.45x = 1,356,482.55
5. Step 5: Solve for x
   x = 1,356,482.55/1,287.45
6. Step 6: Final answer
   x = 1,053.62