Finding the Fourth Proportional to 1,275.18, 1,759.71 and 715.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,275.18 : 1,759.71 = 715.71 : x
2. Step 2: Convert to fraction form
   1,275.18/1,759.71 = 715.71/x
3. Step 3: Cross multiply
   1,275.18x = 1,759.71 × 715.71
4. Step 4: Simplify right side
   1,275.18x = 1,259,442.04
5. Step 5: Solve for x
   x = 1,259,442.04/1,275.18
6. Step 6: Final answer
   x = 987.66