Finding the Fourth Proportional to 1,411.20, 1,945.28 and 913.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,411.20 : 1,945.28 = 913.76 : x
2. Step 2: Convert to fraction form
   1,411.20/1,945.28 = 913.76/x
3. Step 3: Cross multiply
   1,411.20x = 1,945.28 × 913.76
4. Step 4: Simplify right side
   1,411.20x = 1,777,519.05
5. Step 5: Solve for x
   x = 1,777,519.05/1,411.20
6. Step 6: Final answer
   x = 1,259.58