Finding the Fourth Proportional to 1,144.02, 1,578.74 and 620.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,144.02 : 1,578.74 = 620.05 : x
2. Step 2: Convert to fraction form
   1,144.02/1,578.74 = 620.05/x
3. Step 3: Cross multiply
   1,144.02x = 1,578.74 × 620.05
4. Step 4: Simplify right side
   1,144.02x = 978,897.74
5. Step 5: Solve for x
   x = 978,897.74/1,144.02
6. Step 6: Final answer
   x = 855.66