Finding the Fourth Proportional to 1,145.33, 1,580.56 and 621.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.33 : 1,580.56 = 621.36 : x
2. Step 2: Convert to fraction form
   1,145.33/1,580.56 = 621.36/x
3. Step 3: Cross multiply
   1,145.33x = 1,580.56 × 621.36
4. Step 4: Simplify right side
   1,145.33x = 982,096.76
5. Step 5: Solve for x
   x = 982,096.76/1,145.33
6. Step 6: Final answer
   x = 857.48