Finding the Fourth Proportional to 2,856.31, 4,284.55 and 776.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,856.31 : 4,284.55 = 776.30 : x
2. Step 2: Convert to fraction form
   2,856.31/4,284.55 = 776.30/x
3. Step 3: Cross multiply
   2,856.31x = 4,284.55 × 776.30
4. Step 4: Simplify right side
   2,856.31x = 3,326,096.17
5. Step 5: Solve for x
   x = 3,326,096.17/2,856.31
6. Step 6: Final answer
   x = 1,164.47