Finding the Fourth Proportional to 1,020.23, 1,407.90 and 572.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.23 : 1,407.90 = 572.10 : x
2. Step 2: Convert to fraction form
   1,020.23/1,407.90 = 572.10/x
3. Step 3: Cross multiply
   1,020.23x = 1,407.90 × 572.10
4. Step 4: Simplify right side
   1,020.23x = 805,449.69
5. Step 5: Solve for x
   x = 805,449.69/1,020.23
6. Step 6: Final answer
   x = 789.48