Finding the Third Proportional to 138,910 and 210,302.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,910 : 210,302.50 = 210,302.50 : x
2. Step 2: Convert to fraction form
   138,910/210,302.50 = 210,302.50/x
3. Step 3: Cross multiply
   138,910x = 210,302.50 × 210,302.50
4. Step 4: Simplify right side
   138,910x = 44,227,141,506.25
5. Step 5: Solve for x
   x = 44,227,141,506.25/138,910
6. Step 6: Final answer
   x = 318,387.02