Finding the Fourth Proportional to 1,020.04, 1,407.72 and 578.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.04 : 1,407.72 = 578.02 : x
2. Step 2: Convert to fraction form
   1,020.04/1,407.72 = 578.02/x
3. Step 3: Cross multiply
   1,020.04x = 1,407.72 × 578.02
4. Step 4: Simplify right side
   1,020.04x = 813,690.31
5. Step 5: Solve for x
   x = 813,690.31/1,020.04
6. Step 6: Final answer
   x = 797.70