Finding the Third Proportional to 31,909.78 and 69,415.31

Step by Step Solution

1. Step 1: Write the proportion equation
   31,909.78 : 69,415.31 = 69,415.31 : x
2. Step 2: Convert to fraction form
   31,909.78/69,415.31 = 69,415.31/x
3. Step 3: Cross multiply
   31,909.78x = 69,415.31 × 69,415.31
4. Step 4: Simplify right side
   31,909.78x = 4,818,485,609.47
5. Step 5: Solve for x
   x = 4,818,485,609.47/31,909.78
6. Step 6: Final answer
   x = 151,003.40