Finding the Fourth Proportional to 1,013.15, 1,397.94 and 718.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,013.15 : 1,397.94 = 718.31 : x
2. Step 2: Convert to fraction form
   1,013.15/1,397.94 = 718.31/x
3. Step 3: Cross multiply
   1,013.15x = 1,397.94 × 718.31
4. Step 4: Simplify right side
   1,013.15x = 1,004,154.28
5. Step 5: Solve for x
   x = 1,004,154.28/1,013.15
6. Step 6: Final answer
   x = 991.12