Finding the Fourth Proportional to 10,100.79, 15,141.47 and 5,172.75

Step by Step Solution

1. Step 1: Write the proportion equation
   10,100.79 : 15,141.47 = 5,172.75 : x
2. Step 2: Convert to fraction form
   10,100.79/15,141.47 = 5,172.75/x
3. Step 3: Cross multiply
   10,100.79x = 15,141.47 × 5,172.75
4. Step 4: Simplify right side
   10,100.79x = 78,323,013.08
5. Step 5: Solve for x
   x = 78,323,013.08/10,100.79
6. Step 6: Final answer
   x = 7,754.15