Finding the Fourth Proportional to 12,912.01, 19,367.40 and 5,115.35

Step by Step Solution

1. Step 1: Write the proportion equation
   12,912.01 : 19,367.40 = 5,115.35 : x
2. Step 2: Convert to fraction form
   12,912.01/19,367.40 = 5,115.35/x
3. Step 3: Cross multiply
   12,912.01x = 19,367.40 × 5,115.35
4. Step 4: Simplify right side
   12,912.01x = 99,071,029.59
5. Step 5: Solve for x
   x = 99,071,029.59/12,912.01
6. Step 6: Final answer
   x = 7,672.78