Finding the Fourth Proportional to 1,020.69, 1,408.37 and 622.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.69 : 1,408.37 = 622.28 : x
2. Step 2: Convert to fraction form
   1,020.69/1,408.37 = 622.28/x
3. Step 3: Cross multiply
   1,020.69x = 1,408.37 × 622.28
4. Step 4: Simplify right side
   1,020.69x = 876,390.33
5. Step 5: Solve for x
   x = 876,390.33/1,020.69
6. Step 6: Final answer
   x = 858.63