Finding the Fourth Proportional to 1,265.28, 1,897.56 and 648.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,265.28 : 1,897.56 = 648.78 : x
2. Step 2: Convert to fraction form
   1,265.28/1,897.56 = 648.78/x
3. Step 3: Cross multiply
   1,265.28x = 1,897.56 × 648.78
4. Step 4: Simplify right side
   1,265.28x = 1,231,098.98
5. Step 5: Solve for x
   x = 1,231,098.98/1,265.28
6. Step 6: Final answer
   x = 972.99