Finding the Fourth Proportional to 1,290.12, 1,780.27 and 730.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.12 : 1,780.27 = 730.74 : x
2. Step 2: Convert to fraction form
   1,290.12/1,780.27 = 730.74/x
3. Step 3: Cross multiply
   1,290.12x = 1,780.27 × 730.74
4. Step 4: Simplify right side
   1,290.12x = 1,300,914.50
5. Step 5: Solve for x
   x = 1,300,914.50/1,290.12
6. Step 6: Final answer
   x = 1,008.37