Finding the Fourth Proportional to 1,724.24, 2,379.40 and 978.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.24 : 2,379.40 = 978.28 : x
2. Step 2: Convert to fraction form
   1,724.24/2,379.40 = 978.28/x
3. Step 3: Cross multiply
   1,724.24x = 2,379.40 × 978.28
4. Step 4: Simplify right side
   1,724.24x = 2,327,719.43
5. Step 5: Solve for x
   x = 2,327,719.43/1,724.24
6. Step 6: Final answer
   x = 1,350.00