Finding the Fourth Proportional to 1,247.58, 1,721.59 and 716.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,247.58 : 1,721.59 = 716.38 : x
2. Step 2: Convert to fraction form
   1,247.58/1,721.59 = 716.38/x
3. Step 3: Cross multiply
   1,247.58x = 1,721.59 × 716.38
4. Step 4: Simplify right side
   1,247.58x = 1,233,306.55
5. Step 5: Solve for x
   x = 1,233,306.55/1,247.58
6. Step 6: Final answer
   x = 988.56