Finding the Fourth Proportional to 1,020.52, 1,407.78 and 578.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.52 : 1,407.78 = 578.32 : x
2. Step 2: Convert to fraction form
   1,020.52/1,407.78 = 578.32/x
3. Step 3: Cross multiply
   1,020.52x = 1,407.78 × 578.32
4. Step 4: Simplify right side
   1,020.52x = 814,147.33
5. Step 5: Solve for x
   x = 814,147.33/1,020.52
6. Step 6: Final answer
   x = 797.78