Finding the Fourth Proportional to 1,020.22, 1,407.89 and 578.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.22 : 1,407.89 = 578.12 : x
2. Step 2: Convert to fraction form
   1,020.22/1,407.89 = 578.12/x
3. Step 3: Cross multiply
   1,020.22x = 1,407.89 × 578.12
4. Step 4: Simplify right side
   1,020.22x = 813,923.77
5. Step 5: Solve for x
   x = 813,923.77/1,020.22
6. Step 6: Final answer
   x = 797.79