Finding the Fourth Proportional to 1,008.78, 1,392.08 and 566.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.78 : 1,392.08 = 566.72 : x
2. Step 2: Convert to fraction form
   1,008.78/1,392.08 = 566.72/x
3. Step 3: Cross multiply
   1,008.78x = 1,392.08 × 566.72
4. Step 4: Simplify right side
   1,008.78x = 788,919.58
5. Step 5: Solve for x
   x = 788,919.58/1,008.78
6. Step 6: Final answer
   x = 782.05