Finding the Fourth Proportional to 2,928.96, 4,390.20 and 978.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,928.96 : 4,390.20 = 978.48 : x
2. Step 2: Convert to fraction form
   2,928.96/4,390.20 = 978.48/x
3. Step 3: Cross multiply
   2,928.96x = 4,390.20 × 978.48
4. Step 4: Simplify right side
   2,928.96x = 4,295,722.90
5. Step 5: Solve for x
   x = 4,295,722.90/2,928.96
6. Step 6: Final answer
   x = 1,466.64