Finding the Third Proportional to 20,257.50 and 42,129

Step by Step Solution

1. Step 1: Write the proportion equation
   20,257.50 : 42,129 = 42,129 : x
2. Step 2: Convert to fraction form
   20,257.50/42,129 = 42,129/x
3. Step 3: Cross multiply
   20,257.50x = 42,129 × 42,129
4. Step 4: Simplify right side
   20,257.50x = 1,774,852,641
5. Step 5: Solve for x
   x = 1,774,852,641/20,257.50
6. Step 6: Final answer
   x = 87,614.59