Finding the Third Proportional to 7,830.50 and 12,139

Step by Step Solution

1. Step 1: Write the proportion equation
   7,830.50 : 12,139 = 12,139 : x
2. Step 2: Convert to fraction form
   7,830.50/12,139 = 12,139/x
3. Step 3: Cross multiply
   7,830.50x = 12,139 × 12,139
4. Step 4: Simplify right side
   7,830.50x = 147,355,321
5. Step 5: Solve for x
   x = 147,355,321/7,830.50
6. Step 6: Final answer
   x = 18,818.12