Finding the Third Proportional to 300,830 and 643,132

Step by Step Solution

1. Step 1: Write the proportion equation
   300,830 : 643,132 = 643,132 : x
2. Step 2: Convert to fraction form
   300,830/643,132 = 643,132/x
3. Step 3: Cross multiply
   300,830x = 643,132 × 643,132
4. Step 4: Simplify right side
   300,830x = 413,618,769,424
5. Step 5: Solve for x
   x = 413,618,769,424/300,830
6. Step 6: Final answer
   x = 1,374,925.27