Finding the Fourth Proportional to 1,145.46, 1,580.69 and 621.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.46 : 1,580.69 = 621.48 : x
2. Step 2: Convert to fraction form
   1,145.46/1,580.69 = 621.48/x
3. Step 3: Cross multiply
   1,145.46x = 1,580.69 × 621.48
4. Step 4: Simplify right side
   1,145.46x = 982,368.77
5. Step 5: Solve for x
   x = 982,368.77/1,145.46
6. Step 6: Final answer
   x = 857.62