Finding the Fourth Proportional to 1,245.53, 1,718.79 and 685.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,245.53 : 1,718.79 = 685.98 : x
2. Step 2: Convert to fraction form
   1,245.53/1,718.79 = 685.98/x
3. Step 3: Cross multiply
   1,245.53x = 1,718.79 × 685.98
4. Step 4: Simplify right side
   1,245.53x = 1,179,055.56
5. Step 5: Solve for x
   x = 1,179,055.56/1,245.53
6. Step 6: Final answer
   x = 946.63