Finding the Third Proportional to 8,370 and 12,820.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,370 : 12,820.50 = 12,820.50 : x
2. Step 2: Convert to fraction form
   8,370/12,820.50 = 12,820.50/x
3. Step 3: Cross multiply
   8,370x = 12,820.50 × 12,820.50
4. Step 4: Simplify right side
   8,370x = 164,365,220.25
5. Step 5: Solve for x
   x = 164,365,220.25/8,370
6. Step 6: Final answer
   x = 19,637.42