Finding the Fourth Proportional to 8,638.38, 12,956.96 and 3,090.69

Step by Step Solution

1. Step 1: Write the proportion equation
   8,638.38 : 12,956.96 = 3,090.69 : x
2. Step 2: Convert to fraction form
   8,638.38/12,956.96 = 3,090.69/x
3. Step 3: Cross multiply
   8,638.38x = 12,956.96 × 3,090.69
4. Step 4: Simplify right side
   8,638.38x = 40,045,954.43
5. Step 5: Solve for x
   x = 40,045,954.43/8,638.38
6. Step 6: Final answer
   x = 4,635.82