Finding the Fourth Proportional to 1,057.88, 1,459.78 and 615.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,057.88 : 1,459.78 = 615.72 : x
2. Step 2: Convert to fraction form
   1,057.88/1,459.78 = 615.72/x
3. Step 3: Cross multiply
   1,057.88x = 1,459.78 × 615.72
4. Step 4: Simplify right side
   1,057.88x = 898,815.74
5. Step 5: Solve for x
   x = 898,815.74/1,057.88
6. Step 6: Final answer
   x = 849.64