Finding the Fourth Proportional to 1,020.72, 1,407.96 and 627.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.72 : 1,407.96 = 627.42 : x
2. Step 2: Convert to fraction form
   1,020.72/1,407.96 = 627.42/x
3. Step 3: Cross multiply
   1,020.72x = 1,407.96 × 627.42
4. Step 4: Simplify right side
   1,020.72x = 883,382.26
5. Step 5: Solve for x
   x = 883,382.26/1,020.72
6. Step 6: Final answer
   x = 865.45