Finding the Fourth Proportional to 1,620.20, 2,428.89 and 1,374.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,620.20 : 2,428.89 = 1,374.99 : x
2. Step 2: Convert to fraction form
   1,620.20/2,428.89 = 1,374.99/x
3. Step 3: Cross multiply
   1,620.20x = 2,428.89 × 1,374.99
4. Step 4: Simplify right side
   1,620.20x = 3,339,698.86
5. Step 5: Solve for x
   x = 3,339,698.86/1,620.20
6. Step 6: Final answer
   x = 2,061.28