Finding the Fourth Proportional to 1,290.07, 1,780.10 and 730.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.07 : 1,780.10 = 730.43 : x
2. Step 2: Convert to fraction form
   1,290.07/1,780.10 = 730.43/x
3. Step 3: Cross multiply
   1,290.07x = 1,780.10 × 730.43
4. Step 4: Simplify right side
   1,290.07x = 1,300,225.89
5. Step 5: Solve for x
   x = 1,300,225.89/1,290.07
6. Step 6: Final answer
   x = 1,007.87