Finding the Fourth Proportional to 1,145.94, 1,581.41 and 621.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.94 : 1,581.41 = 621.98 : x
2. Step 2: Convert to fraction form
   1,145.94/1,581.41 = 621.98/x
3. Step 3: Cross multiply
   1,145.94x = 1,581.41 × 621.98
4. Step 4: Simplify right side
   1,145.94x = 983,605.39
5. Step 5: Solve for x
   x = 983,605.39/1,145.94
6. Step 6: Final answer
   x = 858.34