Finding the Fourth Proportional to 1,242.37, 1,714.72 and 718.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,242.37 : 1,714.72 = 718.57 : x
2. Step 2: Convert to fraction form
   1,242.37/1,714.72 = 718.57/x
3. Step 3: Cross multiply
   1,242.37x = 1,714.72 × 718.57
4. Step 4: Simplify right side
   1,242.37x = 1,232,137.78
5. Step 5: Solve for x
   x = 1,232,137.78/1,242.37
6. Step 6: Final answer
   x = 991.77