Finding the Third Proportional to 7,881.75 and 12,899.25

Step by Step Solution

1. Step 1: Write the proportion equation
   7,881.75 : 12,899.25 = 12,899.25 : x
2. Step 2: Convert to fraction form
   7,881.75/12,899.25 = 12,899.25/x
3. Step 3: Cross multiply
   7,881.75x = 12,899.25 × 12,899.25
4. Step 4: Simplify right side
   7,881.75x = 166,390,650.56
5. Step 5: Solve for x
   x = 166,390,650.56/7,881.75
6. Step 6: Final answer
   x = 21,110.88