Finding the Fourth Proportional to 1,019.69, 1,406.74 and 621.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.69 : 1,406.74 = 621.24 : x
2. Step 2: Convert to fraction form
   1,019.69/1,406.74 = 621.24/x
3. Step 3: Cross multiply
   1,019.69x = 1,406.74 × 621.24
4. Step 4: Simplify right side
   1,019.69x = 873,931.11
5. Step 5: Solve for x
   x = 873,931.11/1,019.69
6. Step 6: Final answer
   x = 857.06