Finding the Fourth Proportional to 1,014.72, 1,400.34 and 621.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,014.72 : 1,400.34 = 621.53 : x
2. Step 2: Convert to fraction form
   1,014.72/1,400.34 = 621.53/x
3. Step 3: Cross multiply
   1,014.72x = 1,400.34 × 621.53
4. Step 4: Simplify right side
   1,014.72x = 870,346.32
5. Step 5: Solve for x
   x = 870,346.32/1,014.72
6. Step 6: Final answer
   x = 857.72