Finding the Third Proportional to 7,878.38 and 12,199.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,878.38 : 12,199.50 = 12,199.50 : x
2. Step 2: Convert to fraction form
   7,878.38/12,199.50 = 12,199.50/x
3. Step 3: Cross multiply
   7,878.38x = 12,199.50 × 12,199.50
4. Step 4: Simplify right side
   7,878.38x = 148,827,800.25
5. Step 5: Solve for x
   x = 148,827,800.25/7,878.38
6. Step 6: Final answer
   x = 18,890.67