Finding the Fourth Proportional to 1,113.10, 1,536.06 and 615.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,113.10 : 1,536.06 = 615.78 : x
2. Step 2: Convert to fraction form
   1,113.10/1,536.06 = 615.78/x
3. Step 3: Cross multiply
   1,113.10x = 1,536.06 × 615.78
4. Step 4: Simplify right side
   1,113.10x = 945,875.03
5. Step 5: Solve for x
   x = 945,875.03/1,113.10
6. Step 6: Final answer
   x = 849.77