Finding the Third Proportional to 386,911.69 and 434,889

Step by Step Solution

1. Step 1: Write the proportion equation
   386,911.69 : 434,889 = 434,889 : x
2. Step 2: Convert to fraction form
   386,911.69/434,889 = 434,889/x
3. Step 3: Cross multiply
   386,911.69x = 434,889 × 434,889
4. Step 4: Simplify right side
   386,911.69x = 189,128,442,321
5. Step 5: Solve for x
   x = 189,128,442,321/386,911.69
6. Step 6: Final answer
   x = 488,815.53