Finding the Fourth Proportional to 1,143.91, 1,578.60 and 619.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.91 : 1,578.60 = 619.94 : x
2. Step 2: Convert to fraction form
   1,143.91/1,578.60 = 619.94/x
3. Step 3: Cross multiply
   1,143.91x = 1,578.60 × 619.94
4. Step 4: Simplify right side
   1,143.91x = 978,637.28
5. Step 5: Solve for x
   x = 978,637.28/1,143.91
6. Step 6: Final answer
   x = 855.52