Finding the Fourth Proportional to 1,724.76, 2,380.19 and 978.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.76 : 2,380.19 = 978.89 : x
2. Step 2: Convert to fraction form
   1,724.76/2,380.19 = 978.89/x
3. Step 3: Cross multiply
   1,724.76x = 2,380.19 × 978.89
4. Step 4: Simplify right side
   1,724.76x = 2,329,927.39
5. Step 5: Solve for x
   x = 2,329,927.39/1,724.76
6. Step 6: Final answer
   x = 1,350.87