Finding the Fourth Proportional to 1,245.74, 1,719.16 and 686.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,245.74 : 1,719.16 = 686.25 : x
2. Step 2: Convert to fraction form
   1,245.74/1,719.16 = 686.25/x
3. Step 3: Cross multiply
   1,245.74x = 1,719.16 × 686.25
4. Step 4: Simplify right side
   1,245.74x = 1,179,775.27
5. Step 5: Solve for x
   x = 1,179,775.27/1,245.74
6. Step 6: Final answer
   x = 947.05