Finding the Fourth Proportional to 1,287.86, 1,943.33 and 1,242.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.86 : 1,943.33 = 1,242.09 : x
2. Step 2: Convert to fraction form
   1,287.86/1,943.33 = 1,242.09/x
3. Step 3: Cross multiply
   1,287.86x = 1,943.33 × 1,242.09
4. Step 4: Simplify right side
   1,287.86x = 2,413,784.55
5. Step 5: Solve for x
   x = 2,413,784.55/1,287.86
6. Step 6: Final answer
   x = 1,874.27