Finding the Third Proportional to 8,307.56 and 12,870.56

Step by Step Solution

1. Step 1: Write the proportion equation
   8,307.56 : 12,870.56 = 12,870.56 : x
2. Step 2: Convert to fraction form
   8,307.56/12,870.56 = 12,870.56/x
3. Step 3: Cross multiply
   8,307.56x = 12,870.56 × 12,870.56
4. Step 4: Simplify right side
   8,307.56x = 165,651,379.07
5. Step 5: Solve for x
   x = 165,651,379.07/8,307.56
6. Step 6: Final answer
   x = 19,939.83