Finding the Third Proportional to 9,090 and 12,890

Step by Step Solution

1. Step 1: Write the proportion equation
   9,090 : 12,890 = 12,890 : x
2. Step 2: Convert to fraction form
   9,090/12,890 = 12,890/x
3. Step 3: Cross multiply
   9,090x = 12,890 × 12,890
4. Step 4: Simplify right side
   9,090x = 166,152,100
5. Step 5: Solve for x
   x = 166,152,100/9,090
6. Step 6: Final answer
   x = 18,278.56