Finding the Fourth Proportional to 1,724.80, 2,380.32 and 978.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.80 : 2,380.32 = 978.48 : x
2. Step 2: Convert to fraction form
   1,724.80/2,380.32 = 978.48/x
3. Step 3: Cross multiply
   1,724.80x = 2,380.32 × 978.48
4. Step 4: Simplify right side
   1,724.80x = 2,329,095.51
5. Step 5: Solve for x
   x = 2,329,095.51/1,724.80
6. Step 6: Final answer
   x = 1,350.36