Finding the Third Proportional to 30,979.50 and 67,890

Step by Step Solution

1. Step 1: Write the proportion equation
   30,979.50 : 67,890 = 67,890 : x
2. Step 2: Convert to fraction form
   30,979.50/67,890 = 67,890/x
3. Step 3: Cross multiply
   30,979.50x = 67,890 × 67,890
4. Step 4: Simplify right side
   30,979.50x = 4,609,052,100
5. Step 5: Solve for x
   x = 4,609,052,100/30,979.50
6. Step 6: Final answer
   x = 148,777.49