Finding the Third Proportional to 138,510 and 298,890

Step by Step Solution

1. Step 1: Write the proportion equation
   138,510 : 298,890 = 298,890 : x
2. Step 2: Convert to fraction form
   138,510/298,890 = 298,890/x
3. Step 3: Cross multiply
   138,510x = 298,890 × 298,890
4. Step 4: Simplify right side
   138,510x = 89,335,232,100
5. Step 5: Solve for x
   x = 89,335,232,100/138,510
6. Step 6: Final answer
   x = 644,973.16