Finding the Fourth Proportional to 1,290.62, 1,781.83 and 818.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.62 : 1,781.83 = 818.59 : x
2. Step 2: Convert to fraction form
   1,290.62/1,781.83 = 818.59/x
3. Step 3: Cross multiply
   1,290.62x = 1,781.83 × 818.59
4. Step 4: Simplify right side
   1,290.62x = 1,458,579.31
5. Step 5: Solve for x
   x = 1,458,579.31/1,290.62
6. Step 6: Final answer
   x = 1,130.14