Finding the Fourth Proportional to 13,161.31, 19,719.69 and 7,956.25

Step by Step Solution

1. Step 1: Write the proportion equation
   13,161.31 : 19,719.69 = 7,956.25 : x
2. Step 2: Convert to fraction form
   13,161.31/19,719.69 = 7,956.25/x
3. Step 3: Cross multiply
   13,161.31x = 19,719.69 × 7,956.25
4. Step 4: Simplify right side
   13,161.31x = 156,894,783.56
5. Step 5: Solve for x
   x = 156,894,783.56/13,161.31
6. Step 6: Final answer
   x = 11,920.91