Finding the Third Proportional to 19,890.56 and 42,509.81

Step by Step Solution

1. Step 1: Write the proportion equation
   19,890.56 : 42,509.81 = 42,509.81 : x
2. Step 2: Convert to fraction form
   19,890.56/42,509.81 = 42,509.81/x
3. Step 3: Cross multiply
   19,890.56x = 42,509.81 × 42,509.81
4. Step 4: Simplify right side
   19,890.56x = 1,807,084,158.79
5. Step 5: Solve for x
   x = 1,807,084,158.79/19,890.56
6. Step 6: Final answer
   x = 90,851.34