Finding the Third Proportional to 12,120 and 16,290

Step by Step Solution

1. Step 1: Write the proportion equation
   12,120 : 16,290 = 16,290 : x
2. Step 2: Convert to fraction form
   12,120/16,290 = 16,290/x
3. Step 3: Cross multiply
   12,120x = 16,290 × 16,290
4. Step 4: Simplify right side
   12,120x = 265,364,100
5. Step 5: Solve for x
   x = 265,364,100/12,120
6. Step 6: Final answer
   x = 21,894.73