Finding the Fourth Proportional to 1,724.39, 2,379.74 and 978.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.39 : 2,379.74 = 978.38 : x
2. Step 2: Convert to fraction form
   1,724.39/2,379.74 = 978.38/x
3. Step 3: Cross multiply
   1,724.39x = 2,379.74 × 978.38
4. Step 4: Simplify right side
   1,724.39x = 2,328,273.23
5. Step 5: Solve for x
   x = 2,328,273.23/1,724.39
6. Step 6: Final answer
   x = 1,350.20