Finding the Fourth Proportional to 2,880.61, 4,320.89 and 1,320.17

Step by Step Solution

1. Step 1: Write the proportion equation
   2,880.61 : 4,320.89 = 1,320.17 : x
2. Step 2: Convert to fraction form
   2,880.61/4,320.89 = 1,320.17/x
3. Step 3: Cross multiply
   2,880.61x = 4,320.89 × 1,320.17
4. Step 4: Simplify right side
   2,880.61x = 5,704,318.50
5. Step 5: Solve for x
   x = 5,704,318.50/2,880.61
6. Step 6: Final answer
   x = 1,980.25