Finding the Fourth Proportional to 9,268.70, 12,790.31 and 5,290.18

Step by Step Solution

1. Step 1: Write the proportion equation
   9,268.70 : 12,790.31 = 5,290.18 : x
2. Step 2: Convert to fraction form
   9,268.70/12,790.31 = 5,290.18/x
3. Step 3: Cross multiply
   9,268.70x = 12,790.31 × 5,290.18
4. Step 4: Simplify right side
   9,268.70x = 67,663,042.16
5. Step 5: Solve for x
   x = 67,663,042.16/9,268.70
6. Step 6: Final answer
   x = 7,300.17