Finding the Third Proportional to 19,878 and 42,126

Step by Step Solution

1. Step 1: Write the proportion equation
   19,878 : 42,126 = 42,126 : x
2. Step 2: Convert to fraction form
   19,878/42,126 = 42,126/x
3. Step 3: Cross multiply
   19,878x = 42,126 × 42,126
4. Step 4: Simplify right side
   19,878x = 1,774,599,876
5. Step 5: Solve for x
   x = 1,774,599,876/19,878
6. Step 6: Final answer
   x = 89,274.57