Finding the Fourth Proportional to 1,143.98, 1,578.69 and 620.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.98 : 1,578.69 = 620.01 : x
2. Step 2: Convert to fraction form
   1,143.98/1,578.69 = 620.01/x
3. Step 3: Cross multiply
   1,143.98x = 1,578.69 × 620.01
4. Step 4: Simplify right side
   1,143.98x = 978,803.59
5. Step 5: Solve for x
   x = 978,803.59/1,143.98
6. Step 6: Final answer
   x = 855.61