Finding the Third Proportional to 165,640 and 258,300

Step by Step Solution

1. Step 1: Write the proportion equation
   165,640 : 258,300 = 258,300 : x
2. Step 2: Convert to fraction form
   165,640/258,300 = 258,300/x
3. Step 3: Cross multiply
   165,640x = 258,300 × 258,300
4. Step 4: Simplify right side
   165,640x = 66,718,890,000
5. Step 5: Solve for x
   x = 66,718,890,000/165,640
6. Step 6: Final answer
   x = 402,794.55