Finding the Fourth Proportional to 9,191.62, 12,686.69 and 5,215.06

Step by Step Solution

1. Step 1: Write the proportion equation
   9,191.62 : 12,686.69 = 5,215.06 : x
2. Step 2: Convert to fraction form
   9,191.62/12,686.69 = 5,215.06/x
3. Step 3: Cross multiply
   9,191.62x = 12,686.69 × 5,215.06
4. Step 4: Simplify right side
   9,191.62x = 66,161,849.55
5. Step 5: Solve for x
   x = 66,161,849.55/9,191.62
6. Step 6: Final answer
   x = 7,198.06