Finding the Third Proportional to 7,978.50 and 17,688.38

Step by Step Solution

1. Step 1: Write the proportion equation
   7,978.50 : 17,688.38 = 17,688.38 : x
2. Step 2: Convert to fraction form
   7,978.50/17,688.38 = 17,688.38/x
3. Step 3: Cross multiply
   7,978.50x = 17,688.38 × 17,688.38
4. Step 4: Simplify right side
   7,978.50x = 312,878,610.14
5. Step 5: Solve for x
   x = 312,878,610.14/7,978.50
6. Step 6: Final answer
   x = 39,215.22