Finding the Fourth Proportional to 1,245.59, 1,718.88 and 686.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,245.59 : 1,718.88 = 686.05 : x
2. Step 2: Convert to fraction form
   1,245.59/1,718.88 = 686.05/x
3. Step 3: Cross multiply
   1,245.59x = 1,718.88 × 686.05
4. Step 4: Simplify right side
   1,245.59x = 1,179,233.33
5. Step 5: Solve for x
   x = 1,179,233.33/1,245.59
6. Step 6: Final answer
   x = 946.73