Finding the Third Proportional to 42,690 and 67,878

Step by Step Solution

1. Step 1: Write the proportion equation
   42,690 : 67,878 = 67,878 : x
2. Step 2: Convert to fraction form
   42,690/67,878 = 67,878/x
3. Step 3: Cross multiply
   42,690x = 67,878 × 67,878
4. Step 4: Simplify right side
   42,690x = 4,607,422,884
5. Step 5: Solve for x
   x = 4,607,422,884/42,690
6. Step 6: Final answer
   x = 107,927.45