Finding the Fourth Proportional to 1,145.82, 1,581.24 and 621.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.82 : 1,581.24 = 621.87 : x
2. Step 2: Convert to fraction form
   1,145.82/1,581.24 = 621.87/x
3. Step 3: Cross multiply
   1,145.82x = 1,581.24 × 621.87
4. Step 4: Simplify right side
   1,145.82x = 983,325.72
5. Step 5: Solve for x
   x = 983,325.72/1,145.82
6. Step 6: Final answer
   x = 858.19