Finding the Third Proportional to 140,090 and 209,640

Step by Step Solution

1. Step 1: Write the proportion equation
   140,090 : 209,640 = 209,640 : x
2. Step 2: Convert to fraction form
   140,090/209,640 = 209,640/x
3. Step 3: Cross multiply
   140,090x = 209,640 × 209,640
4. Step 4: Simplify right side
   140,090x = 43,948,929,600
5. Step 5: Solve for x
   x = 43,948,929,600/140,090
6. Step 6: Final answer
   x = 313,719.25