Finding the Fourth Proportional to 2,623.10, 3,929.52 and 1,388.81

Step by Step Solution

1. Step 1: Write the proportion equation
   2,623.10 : 3,929.52 = 1,388.81 : x
2. Step 2: Convert to fraction form
   2,623.10/3,929.52 = 1,388.81/x
3. Step 3: Cross multiply
   2,623.10x = 3,929.52 × 1,388.81
4. Step 4: Simplify right side
   2,623.10x = 5,457,366.50
5. Step 5: Solve for x
   x = 5,457,366.50/2,623.10
6. Step 6: Final answer
   x = 2,080.50