Finding the Fourth Proportional to 2,539.66, 3,808.56 and 978.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,539.66 : 3,808.56 = 978.88 : x
2. Step 2: Convert to fraction form
   2,539.66/3,808.56 = 978.88/x
3. Step 3: Cross multiply
   2,539.66x = 3,808.56 × 978.88
4. Step 4: Simplify right side
   2,539.66x = 3,728,123.21
5. Step 5: Solve for x
   x = 3,728,123.21/2,539.66
6. Step 6: Final answer
   x = 1,467.96