Finding the Fourth Proportional to 12,491.77, 17,238.16 and 7,188.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,491.77 : 17,238.16 = 7,188.30 : x
2. Step 2: Convert to fraction form
   12,491.77/17,238.16 = 7,188.30/x
3. Step 3: Cross multiply
   12,491.77x = 17,238.16 × 7,188.30
4. Step 4: Simplify right side
   12,491.77x = 123,913,065.53
5. Step 5: Solve for x
   x = 123,913,065.53/12,491.77
6. Step 6: Final answer
   x = 9,919.58