Finding the Fourth Proportional to 1,339.28, 2,010.72 and 851.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.28 : 2,010.72 = 851.12 : x
2. Step 2: Convert to fraction form
   1,339.28/2,010.72 = 851.12/x
3. Step 3: Cross multiply
   1,339.28x = 2,010.72 × 851.12
4. Step 4: Simplify right side
   1,339.28x = 1,711,364.01
5. Step 5: Solve for x
   x = 1,711,364.01/1,339.28
6. Step 6: Final answer
   x = 1,277.82