Finding the Third Proportional to 138,917 and 215,240

Step by Step Solution

1. Step 1: Write the proportion equation
   138,917 : 215,240 = 215,240 : x
2. Step 2: Convert to fraction form
   138,917/215,240 = 215,240/x
3. Step 3: Cross multiply
   138,917x = 215,240 × 215,240
4. Step 4: Simplify right side
   138,917x = 46,328,257,600
5. Step 5: Solve for x
   x = 46,328,257,600/138,917
6. Step 6: Final answer
   x = 333,495.96