Finding the Fourth Proportional to 1,724.33, 2,380.11 and 978.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.33 : 2,380.11 = 978.78 : x
2. Step 2: Convert to fraction form
   1,724.33/2,380.11 = 978.78/x
3. Step 3: Cross multiply
   1,724.33x = 2,380.11 × 978.78
4. Step 4: Simplify right side
   1,724.33x = 2,329,599.17
5. Step 5: Solve for x
   x = 2,329,599.17/1,724.33
6. Step 6: Final answer
   x = 1,351.02