Finding the Third Proportional to 166,658 and 258,123

Step by Step Solution

1. Step 1: Write the proportion equation
   166,658 : 258,123 = 258,123 : x
2. Step 2: Convert to fraction form
   166,658/258,123 = 258,123/x
3. Step 3: Cross multiply
   166,658x = 258,123 × 258,123
4. Step 4: Simplify right side
   166,658x = 66,627,483,129
5. Step 5: Solve for x
   x = 66,627,483,129/166,658
6. Step 6: Final answer
   x = 399,785.69