Finding the Fourth Proportional to 2,618.58, 3,928.10 and 670.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,618.58 : 3,928.10 = 670.78 : x
2. Step 2: Convert to fraction form
   2,618.58/3,928.10 = 670.78/x
3. Step 3: Cross multiply
   2,618.58x = 3,928.10 × 670.78
4. Step 4: Simplify right side
   2,618.58x = 2,634,892.47
5. Step 5: Solve for x
   x = 2,634,892.47/2,618.58
6. Step 6: Final answer
   x = 1,006.23