Finding the Fourth Proportional to 1,245.50, 1,718.88 and 686.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,245.50 : 1,718.88 = 686.07 : x
2. Step 2: Convert to fraction form
   1,245.50/1,718.88 = 686.07/x
3. Step 3: Cross multiply
   1,245.50x = 1,718.88 × 686.07
4. Step 4: Simplify right side
   1,245.50x = 1,179,272.00
5. Step 5: Solve for x
   x = 1,179,272.00/1,245.50
6. Step 6: Final answer
   x = 946.83