Finding the Fourth Proportional to 1,253.56, 1,729.72 and 715.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,253.56 : 1,729.72 = 715.20 : x
2. Step 2: Convert to fraction form
   1,253.56/1,729.72 = 715.20/x
3. Step 3: Cross multiply
   1,253.56x = 1,729.72 × 715.20
4. Step 4: Simplify right side
   1,253.56x = 1,237,095.74
5. Step 5: Solve for x
   x = 1,237,095.74/1,253.56
6. Step 6: Final answer
   x = 986.87