Finding the Third Proportional to 30,678.75 and 47,139.25

Step by Step Solution

1. Step 1: Write the proportion equation
   30,678.75 : 47,139.25 = 47,139.25 : x
2. Step 2: Convert to fraction form
   30,678.75/47,139.25 = 47,139.25/x
3. Step 3: Cross multiply
   30,678.75x = 47,139.25 × 47,139.25
4. Step 4: Simplify right side
   30,678.75x = 2,222,108,890.56
5. Step 5: Solve for x
   x = 2,222,108,890.56/30,678.75
6. Step 6: Final answer
   x = 72,431.53