Finding the Fourth Proportional to 10,105.12, 15,129.73 and 5,164.12

Step by Step Solution

1. Step 1: Write the proportion equation
   10,105.12 : 15,129.73 = 5,164.12 : x
2. Step 2: Convert to fraction form
   10,105.12/15,129.73 = 5,164.12/x
3. Step 3: Cross multiply
   10,105.12x = 15,129.73 × 5,164.12
4. Step 4: Simplify right side
   10,105.12x = 78,131,741.29
5. Step 5: Solve for x
   x = 78,131,741.29/10,105.12
6. Step 6: Final answer
   x = 7,731.90