Finding the Fourth Proportional to 1,791.72, 2,470.77 and 1,287.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,791.72 : 2,470.77 = 1,287.90 : x
2. Step 2: Convert to fraction form
   1,791.72/2,470.77 = 1,287.90/x
3. Step 3: Cross multiply
   1,791.72x = 2,470.77 × 1,287.90
4. Step 4: Simplify right side
   1,791.72x = 3,182,104.68
5. Step 5: Solve for x
   x = 3,182,104.68/1,791.72
6. Step 6: Final answer
   x = 1,776.01