Finding the Fourth Proportional to 1,019.22, 1,406.18 and 621.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.22 : 1,406.18 = 621.02 : x
2. Step 2: Convert to fraction form
   1,019.22/1,406.18 = 621.02/x
3. Step 3: Cross multiply
   1,019.22x = 1,406.18 × 621.02
4. Step 4: Simplify right side
   1,019.22x = 873,265.90
5. Step 5: Solve for x
   x = 873,265.90/1,019.22
6. Step 6: Final answer
   x = 856.80