Finding the Fourth Proportional to 1,724.65, 2,380.32 and 978.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.65 : 2,380.32 = 978.91 : x
2. Step 2: Convert to fraction form
   1,724.65/2,380.32 = 978.91/x
3. Step 3: Cross multiply
   1,724.65x = 2,380.32 × 978.91
4. Step 4: Simplify right side
   1,724.65x = 2,330,113.10
5. Step 5: Solve for x
   x = 2,330,113.10/1,724.65
6. Step 6: Final answer
   x = 1,351.07