Finding the Fourth Proportional to 1,144.06, 1,578.80 and 620.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,144.06 : 1,578.80 = 620.10 : x
2. Step 2: Convert to fraction form
   1,144.06/1,578.80 = 620.10/x
3. Step 3: Cross multiply
   1,144.06x = 1,578.80 × 620.10
4. Step 4: Simplify right side
   1,144.06x = 979,013.88
5. Step 5: Solve for x
   x = 979,013.88/1,144.06
6. Step 6: Final answer
   x = 855.74