Finding the Fourth Proportional to 1,145.30, 1,580.51 and 621.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.30 : 1,580.51 = 621.33 : x
2. Step 2: Convert to fraction form
   1,145.30/1,580.51 = 621.33/x
3. Step 3: Cross multiply
   1,145.30x = 1,580.51 × 621.33
4. Step 4: Simplify right side
   1,145.30x = 982,018.28
5. Step 5: Solve for x
   x = 982,018.28/1,145.30
6. Step 6: Final answer
   x = 857.43