Finding the Third Proportional to 428,308 and 921,208

Step by Step Solution

1. Step 1: Write the proportion equation
   428,308 : 921,208 = 921,208 : x
2. Step 2: Convert to fraction form
   428,308/921,208 = 921,208/x
3. Step 3: Cross multiply
   428,308x = 921,208 × 921,208
4. Step 4: Simplify right side
   428,308x = 848,624,179,264
5. Step 5: Solve for x
   x = 848,624,179,264/428,308
6. Step 6: Final answer
   x = 1,981,340.95