Finding the Fourth Proportional to 1,105.59, 1,525.78 and 663.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.59 : 1,525.78 = 663.87 : x
2. Step 2: Convert to fraction form
   1,105.59/1,525.78 = 663.87/x
3. Step 3: Cross multiply
   1,105.59x = 1,525.78 × 663.87
4. Step 4: Simplify right side
   1,105.59x = 1,012,919.57
5. Step 5: Solve for x
   x = 1,012,919.57/1,105.59
6. Step 6: Final answer
   x = 916.18