Finding the Third Proportional to 42,991.50 and 66,431.25

Step by Step Solution

1. Step 1: Write the proportion equation
   42,991.50 : 66,431.25 = 66,431.25 : x
2. Step 2: Convert to fraction form
   42,991.50/66,431.25 = 66,431.25/x
3. Step 3: Cross multiply
   42,991.50x = 66,431.25 × 66,431.25
4. Step 4: Simplify right side
   42,991.50x = 4,413,110,976.56
5. Step 5: Solve for x
   x = 4,413,110,976.56/42,991.50
6. Step 6: Final answer
   x = 102,650.78