Finding the Fourth Proportional to 2,619.52, 3,929.22 and 1,320.64

Step by Step Solution

1. Step 1: Write the proportion equation
   2,619.52 : 3,929.22 = 1,320.64 : x
2. Step 2: Convert to fraction form
   2,619.52/3,929.22 = 1,320.64/x
3. Step 3: Cross multiply
   2,619.52x = 3,929.22 × 1,320.64
4. Step 4: Simplify right side
   2,619.52x = 5,189,085.10
5. Step 5: Solve for x
   x = 5,189,085.10/2,619.52
6. Step 6: Final answer
   x = 1,980.93