Finding the Fourth Proportional to 1,913.31, 2,869.61 and 680.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,913.31 : 2,869.61 = 680.72 : x
2. Step 2: Convert to fraction form
   1,913.31/2,869.61 = 680.72/x
3. Step 3: Cross multiply
   1,913.31x = 2,869.61 × 680.72
4. Step 4: Simplify right side
   1,913.31x = 1,953,383.17
5. Step 5: Solve for x
   x = 1,953,383.17/1,913.31
6. Step 6: Final answer
   x = 1,020.94