Finding the Fourth Proportional to 1,143.94, 1,578.65 and 619.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.94 : 1,578.65 = 619.98 : x
2. Step 2: Convert to fraction form
   1,143.94/1,578.65 = 619.98/x
3. Step 3: Cross multiply
   1,143.94x = 1,578.65 × 619.98
4. Step 4: Simplify right side
   1,143.94x = 978,731.43
5. Step 5: Solve for x
   x = 978,731.43/1,143.94
6. Step 6: Final answer
   x = 855.58