Finding the Fourth Proportional to 1,290.66, 1,781.15 and 731.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.66 : 1,781.15 = 731.15 : x
2. Step 2: Convert to fraction form
   1,290.66/1,781.15 = 731.15/x
3. Step 3: Cross multiply
   1,290.66x = 1,781.15 × 731.15
4. Step 4: Simplify right side
   1,290.66x = 1,302,287.82
5. Step 5: Solve for x
   x = 1,302,287.82/1,290.66
6. Step 6: Final answer
   x = 1,009.01