Finding the Third Proportional to 8,638.50 and 12,955.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,638.50 : 12,955.50 = 12,955.50 : x
2. Step 2: Convert to fraction form
   8,638.50/12,955.50 = 12,955.50/x
3. Step 3: Cross multiply
   8,638.50x = 12,955.50 × 12,955.50
4. Step 4: Simplify right side
   8,638.50x = 167,844,980.25
5. Step 5: Solve for x
   x = 167,844,980.25/8,638.50
6. Step 6: Final answer
   x = 19,429.88