Finding the Fourth Proportional to 1,126.80, 1,554.72 and 660.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,126.80 : 1,554.72 = 660.78 : x
2. Step 2: Convert to fraction form
   1,126.80/1,554.72 = 660.78/x
3. Step 3: Cross multiply
   1,126.80x = 1,554.72 × 660.78
4. Step 4: Simplify right side
   1,126.80x = 1,027,327.88
5. Step 5: Solve for x
   x = 1,027,327.88/1,126.80
6. Step 6: Final answer
   x = 911.72