Finding the Fourth Proportional to 2,010.78, 3,017.34 and 856.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,010.78 : 3,017.34 = 856.50 : x
2. Step 2: Convert to fraction form
   2,010.78/3,017.34 = 856.50/x
3. Step 3: Cross multiply
   2,010.78x = 3,017.34 × 856.50
4. Step 4: Simplify right side
   2,010.78x = 2,584,351.71
5. Step 5: Solve for x
   x = 2,584,351.71/2,010.78
6. Step 6: Final answer
   x = 1,285.25