Finding the Fourth Proportional to 1,247.58, 1,721.61 and 723.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,247.58 : 1,721.61 = 723.57 : x
2. Step 2: Convert to fraction form
   1,247.58/1,721.61 = 723.57/x
3. Step 3: Cross multiply
   1,247.58x = 1,721.61 × 723.57
4. Step 4: Simplify right side
   1,247.58x = 1,245,705.35
5. Step 5: Solve for x
   x = 1,245,705.35/1,247.58
6. Step 6: Final answer
   x = 998.50