Finding the Third Proportional to 7,878 and 13,081.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,878 : 13,081.50 = 13,081.50 : x
2. Step 2: Convert to fraction form
   7,878/13,081.50 = 13,081.50/x
3. Step 3: Cross multiply
   7,878x = 13,081.50 × 13,081.50
4. Step 4: Simplify right side
   7,878x = 171,125,642.25
5. Step 5: Solve for x
   x = 171,125,642.25/7,878
6. Step 6: Final answer
   x = 21,721.97