Finding the Third Proportional to 31,715 and 69,707.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,715 : 69,707.50 = 69,707.50 : x
2. Step 2: Convert to fraction form
   31,715/69,707.50 = 69,707.50/x
3. Step 3: Cross multiply
   31,715x = 69,707.50 × 69,707.50
4. Step 4: Simplify right side
   31,715x = 4,859,135,556.25
5. Step 5: Solve for x
   x = 4,859,135,556.25/31,715
6. Step 6: Final answer
   x = 153,212.54