Finding the Fourth Proportional to 1,724.69, 2,380.14 and 978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.69 : 2,380.14 = 978.72 : x
2. Step 2: Convert to fraction form
   1,724.69/2,380.14 = 978.72/x
3. Step 3: Cross multiply
   1,724.69x = 2,380.14 × 978.72
4. Step 4: Simplify right side
   1,724.69x = 2,329,490.62
5. Step 5: Solve for x
   x = 2,329,490.62/1,724.69
6. Step 6: Final answer
   x = 1,350.67