Finding the Fourth Proportional to 2,148.17, 3,221.24 and 978.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,148.17 : 3,221.24 = 978.12 : x
2. Step 2: Convert to fraction form
   2,148.17/3,221.24 = 978.12/x
3. Step 3: Cross multiply
   2,148.17x = 3,221.24 × 978.12
4. Step 4: Simplify right side
   2,148.17x = 3,150,754.38
5. Step 5: Solve for x
   x = 3,150,754.38/2,148.17
6. Step 6: Final answer
   x = 1,466.72