Finding the Fourth Proportional to 2,856.91, 4,285.97 and 1,213.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,856.91 : 4,285.97 = 1,213.42 : x
2. Step 2: Convert to fraction form
   2,856.91/4,285.97 = 1,213.42/x
3. Step 3: Cross multiply
   2,856.91x = 4,285.97 × 1,213.42
4. Step 4: Simplify right side
   2,856.91x = 5,200,681.72
5. Step 5: Solve for x
   x = 5,200,681.72/2,856.91
6. Step 6: Final answer
   x = 1,820.39