Finding the Third Proportional to 8,499.75 and 13,128.75

Step by Step Solution

1. Step 1: Write the proportion equation
   8,499.75 : 13,128.75 = 13,128.75 : x
2. Step 2: Convert to fraction form
   8,499.75/13,128.75 = 13,128.75/x
3. Step 3: Cross multiply
   8,499.75x = 13,128.75 × 13,128.75
4. Step 4: Simplify right side
   8,499.75x = 172,364,076.56
5. Step 5: Solve for x
   x = 172,364,076.56/8,499.75
6. Step 6: Final answer
   x = 20,278.72