Finding the Third Proportional to 3,991.78 and 7,102.69

Step by Step Solution

1. Step 1: Write the proportion equation
   3,991.78 : 7,102.69 = 7,102.69 : x
2. Step 2: Convert to fraction form
   3,991.78/7,102.69 = 7,102.69/x
3. Step 3: Cross multiply
   3,991.78x = 7,102.69 × 7,102.69
4. Step 4: Simplify right side
   3,991.78x = 50,448,169.72
5. Step 5: Solve for x
   x = 50,448,169.72/3,991.78
6. Step 6: Final answer
   x = 12,638.01