Finding the Third Proportional to 31,230 and 64,890

Step by Step Solution

1. Step 1: Write the proportion equation
   31,230 : 64,890 = 64,890 : x
2. Step 2: Convert to fraction form
   31,230/64,890 = 64,890/x
3. Step 3: Cross multiply
   31,230x = 64,890 × 64,890
4. Step 4: Simplify right side
   31,230x = 4,210,712,100
5. Step 5: Solve for x
   x = 4,210,712,100/31,230
6. Step 6: Final answer
   x = 134,829.08