Finding the Fourth Proportional to 12,910.72, 19,368.12 and 5,515.22

Step by Step Solution

1. Step 1: Write the proportion equation
   12,910.72 : 19,368.12 = 5,515.22 : x
2. Step 2: Convert to fraction form
   12,910.72/19,368.12 = 5,515.22/x
3. Step 3: Cross multiply
   12,910.72x = 19,368.12 × 5,515.22
4. Step 4: Simplify right side
   12,910.72x = 106,819,442.79
5. Step 5: Solve for x
   x = 106,819,442.79/12,910.72
6. Step 6: Final answer
   x = 8,273.70