Finding the Fourth Proportional to 1,724.26, 2,379.59 and 978.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.26 : 2,379.59 = 978.21 : x
2. Step 2: Convert to fraction form
   1,724.26/2,379.59 = 978.21/x
3. Step 3: Cross multiply
   1,724.26x = 2,379.59 × 978.21
4. Step 4: Simplify right side
   1,724.26x = 2,327,738.73
5. Step 5: Solve for x
   x = 2,327,738.73/1,724.26
6. Step 6: Final answer
   x = 1,349.99