Finding the Third Proportional to 7,872 and 12,290

Step by Step Solution

1. Step 1: Write the proportion equation
   7,872 : 12,290 = 12,290 : x
2. Step 2: Convert to fraction form
   7,872/12,290 = 12,290/x
3. Step 3: Cross multiply
   7,872x = 12,290 × 12,290
4. Step 4: Simplify right side
   7,872x = 151,044,100
5. Step 5: Solve for x
   x = 151,044,100/7,872
6. Step 6: Final answer
   x = 19,187.51