Finding the Fourth Proportional to 1,145.32, 1,580.55 and 621.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.32 : 1,580.55 = 621.37 : x
2. Step 2: Convert to fraction form
   1,145.32/1,580.55 = 621.37/x
3. Step 3: Cross multiply
   1,145.32x = 1,580.55 × 621.37
4. Step 4: Simplify right side
   1,145.32x = 982,106.35
5. Step 5: Solve for x
   x = 982,106.35/1,145.32
6. Step 6: Final answer
   x = 857.50