Finding the Third Proportional to 66,986 and 90,978

Step by Step Solution

1. Step 1: Write the proportion equation
   66,986 : 90,978 = 90,978 : x
2. Step 2: Convert to fraction form
   66,986/90,978 = 90,978/x
3. Step 3: Cross multiply
   66,986x = 90,978 × 90,978
4. Step 4: Simplify right side
   66,986x = 8,276,996,484
5. Step 5: Solve for x
   x = 8,276,996,484/66,986
6. Step 6: Final answer
   x = 123,563.08