Finding the Third Proportional to 9,142 and 12,389

Step by Step Solution

1. Step 1: Write the proportion equation
   9,142 : 12,389 = 12,389 : x
2. Step 2: Convert to fraction form
   9,142/12,389 = 12,389/x
3. Step 3: Cross multiply
   9,142x = 12,389 × 12,389
4. Step 4: Simplify right side
   9,142x = 153,487,321
5. Step 5: Solve for x
   x = 153,487,321/9,142
6. Step 6: Final answer
   x = 16,789.25