Finding the Fourth Proportional to 2,072.48, 3,108.43 and 839.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,072.48 : 3,108.43 = 839.89 : x
2. Step 2: Convert to fraction form
   2,072.48/3,108.43 = 839.89/x
3. Step 3: Cross multiply
   2,072.48x = 3,108.43 × 839.89
4. Step 4: Simplify right side
   2,072.48x = 2,610,746.60
5. Step 5: Solve for x
   x = 2,610,746.60/2,072.48
6. Step 6: Final answer
   x = 1,259.72