Finding the Fourth Proportional to 12,938.16, 19,409.72 and 4,170.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,938.16 : 19,409.72 = 4,170.72 : x
2. Step 2: Convert to fraction form
   12,938.16/19,409.72 = 4,170.72/x
3. Step 3: Cross multiply
   12,938.16x = 19,409.72 × 4,170.72
4. Step 4: Simplify right side
   12,938.16x = 80,952,507.40
5. Step 5: Solve for x
   x = 80,952,507.40/12,938.16
6. Step 6: Final answer
   x = 6,256.88