Finding the Fourth Proportional to 1,520.40, 2,289.72 and 1,339.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,520.40 : 2,289.72 = 1,339.76 : x
2. Step 2: Convert to fraction form
   1,520.40/2,289.72 = 1,339.76/x
3. Step 3: Cross multiply
   1,520.40x = 2,289.72 × 1,339.76
4. Step 4: Simplify right side
   1,520.40x = 3,067,675.27
5. Step 5: Solve for x
   x = 3,067,675.27/1,520.40
6. Step 6: Final answer
   x = 2,017.68