Finding the Fourth Proportional to 2,086.60, 3,124.50 and 1,217.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.60 : 3,124.50 = 1,217.20 : x
2. Step 2: Convert to fraction form
   2,086.60/3,124.50 = 1,217.20/x
3. Step 3: Cross multiply
   2,086.60x = 3,124.50 × 1,217.20
4. Step 4: Simplify right side
   2,086.60x = 3,803,141.40
5. Step 5: Solve for x
   x = 3,803,141.40/2,086.60
6. Step 6: Final answer
   x = 1,822.65