Finding the Fourth Proportional to 2,147.60, 3,222.97 and 978.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,147.60 : 3,222.97 = 978.92 : x
2. Step 2: Convert to fraction form
   2,147.60/3,222.97 = 978.92/x
3. Step 3: Cross multiply
   2,147.60x = 3,222.97 × 978.92
4. Step 4: Simplify right side
   2,147.60x = 3,155,029.79
5. Step 5: Solve for x
   x = 3,155,029.79/2,147.60
6. Step 6: Final answer
   x = 1,469.10