Finding the Fourth Proportional to 1,143.66, 1,578.25 and 619.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.66 : 1,578.25 = 619.69 : x
2. Step 2: Convert to fraction form
   1,143.66/1,578.25 = 619.69/x
3. Step 3: Cross multiply
   1,143.66x = 1,578.25 × 619.69
4. Step 4: Simplify right side
   1,143.66x = 978,020.25
5. Step 5: Solve for x
   x = 978,020.25/1,143.66
6. Step 6: Final answer
   x = 855.17