Finding the Third Proportional to 59,978 and 85,440

Step by Step Solution

1. Step 1: Write the proportion equation
   59,978 : 85,440 = 85,440 : x
2. Step 2: Convert to fraction form
   59,978/85,440 = 85,440/x
3. Step 3: Cross multiply
   59,978x = 85,440 × 85,440
4. Step 4: Simplify right side
   59,978x = 7,299,993,600
5. Step 5: Solve for x
   x = 7,299,993,600/59,978
6. Step 6: Final answer
   x = 121,711.19