Finding the Third Proportional to 310,645.50 and 679,440

Step by Step Solution

1. Step 1: Write the proportion equation
   310,645.50 : 679,440 = 679,440 : x
2. Step 2: Convert to fraction form
   310,645.50/679,440 = 679,440/x
3. Step 3: Cross multiply
   310,645.50x = 679,440 × 679,440
4. Step 4: Simplify right side
   310,645.50x = 461,638,713,600
5. Step 5: Solve for x
   x = 461,638,713,600/310,645.50
6. Step 6: Final answer
   x = 1,486,062.77