Finding the Fourth Proportional to 9,527.10, 13,221.29 and 9,138.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,527.10 : 13,221.29 = 9,138.30 : x
2. Step 2: Convert to fraction form
   9,527.10/13,221.29 = 9,138.30/x
3. Step 3: Cross multiply
   9,527.10x = 13,221.29 × 9,138.30
4. Step 4: Simplify right side
   9,527.10x = 120,820,068.72
5. Step 5: Solve for x
   x = 120,820,068.72/9,527.10
6. Step 6: Final answer
   x = 12,681.73