Finding the Fourth Proportional to 2,389.28, 3,582.30 and 1,216.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,389.28 : 3,582.30 = 1,216.40 : x
2. Step 2: Convert to fraction form
   2,389.28/3,582.30 = 1,216.40/x
3. Step 3: Cross multiply
   2,389.28x = 3,582.30 × 1,216.40
4. Step 4: Simplify right side
   2,389.28x = 4,357,509.72
5. Step 5: Solve for x
   x = 4,357,509.72/2,389.28
6. Step 6: Final answer
   x = 1,823.78