Finding the Fourth Proportional to 2,808.01, 4,212.42 and 860.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,808.01 : 4,212.42 = 860.50 : x
2. Step 2: Convert to fraction form
   2,808.01/4,212.42 = 860.50/x
3. Step 3: Cross multiply
   2,808.01x = 4,212.42 × 860.50
4. Step 4: Simplify right side
   2,808.01x = 3,624,787.41
5. Step 5: Solve for x
   x = 3,624,787.41/2,808.01
6. Step 6: Final answer
   x = 1,290.87