Finding the Third Proportional to 42,709.78 and 91,990.69

Step by Step Solution

1. Step 1: Write the proportion equation
   42,709.78 : 91,990.69 = 91,990.69 : x
2. Step 2: Convert to fraction form
   42,709.78/91,990.69 = 91,990.69/x
3. Step 3: Cross multiply
   42,709.78x = 91,990.69 × 91,990.69
4. Step 4: Simplify right side
   42,709.78x = 8,462,286,586.72
5. Step 5: Solve for x
   x = 8,462,286,586.72/42,709.78
6. Step 6: Final answer
   x = 198,134.63