Finding the Third Proportional to 166,890 and 258,253.50

Step by Step Solution

1. Step 1: Write the proportion equation
   166,890 : 258,253.50 = 258,253.50 : x
2. Step 2: Convert to fraction form
   166,890/258,253.50 = 258,253.50/x
3. Step 3: Cross multiply
   166,890x = 258,253.50 × 258,253.50
4. Step 4: Simplify right side
   166,890x = 66,694,870,262.25
5. Step 5: Solve for x
   x = 66,694,870,262.25/166,890
6. Step 6: Final answer
   x = 399,633.71