Finding the Fourth Proportional to 1,008.20, 1,390.82 and 614.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.20 : 1,390.82 = 614.54 : x
2. Step 2: Convert to fraction form
   1,008.20/1,390.82 = 614.54/x
3. Step 3: Cross multiply
   1,008.20x = 1,390.82 × 614.54
4. Step 4: Simplify right side
   1,008.20x = 854,704.50
5. Step 5: Solve for x
   x = 854,704.50/1,008.20
6. Step 6: Final answer
   x = 847.76