Finding the Third Proportional to 8,391 and 12,412.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,391 : 12,412.50 = 12,412.50 : x
2. Step 2: Convert to fraction form
   8,391/12,412.50 = 12,412.50/x
3. Step 3: Cross multiply
   8,391x = 12,412.50 × 12,412.50
4. Step 4: Simplify right side
   8,391x = 154,070,156.25
5. Step 5: Solve for x
   x = 154,070,156.25/8,391
6. Step 6: Final answer
   x = 18,361.36