Finding the Fourth Proportional to 1,019.49, 1,406.67 and 621.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.49 : 1,406.67 = 621.06 : x
2. Step 2: Convert to fraction form
   1,019.49/1,406.67 = 621.06/x
3. Step 3: Cross multiply
   1,019.49x = 1,406.67 × 621.06
4. Step 4: Simplify right side
   1,019.49x = 873,626.47
5. Step 5: Solve for x
   x = 873,626.47/1,019.49
6. Step 6: Final answer
   x = 856.93