Finding the Fourth Proportional to 1,105.19, 1,524.78 and 685.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.19 : 1,524.78 = 685.39 : x
2. Step 2: Convert to fraction form
   1,105.19/1,524.78 = 685.39/x
3. Step 3: Cross multiply
   1,105.19x = 1,524.78 × 685.39
4. Step 4: Simplify right side
   1,105.19x = 1,045,062.58
5. Step 5: Solve for x
   x = 1,045,062.58/1,105.19
6. Step 6: Final answer
   x = 945.60