Finding the Fourth Proportional to 2,621.98, 3,930.63 and 978.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,621.98 : 3,930.63 = 978.61 : x
2. Step 2: Convert to fraction form
   2,621.98/3,930.63 = 978.61/x
3. Step 3: Cross multiply
   2,621.98x = 3,930.63 × 978.61
4. Step 4: Simplify right side
   2,621.98x = 3,846,534.17
5. Step 5: Solve for x
   x = 3,846,534.17/2,621.98
6. Step 6: Final answer
   x = 1,467.03