Finding the Fourth Proportional to 1,411.55, 2,114.89 and 978.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,411.55 : 2,114.89 = 978.20 : x
2. Step 2: Convert to fraction form
   1,411.55/2,114.89 = 978.20/x
3. Step 3: Cross multiply
   1,411.55x = 2,114.89 × 978.20
4. Step 4: Simplify right side
   1,411.55x = 2,068,785.40
5. Step 5: Solve for x
   x = 2,068,785.40/1,411.55
6. Step 6: Final answer
   x = 1,465.61