Finding the Third Proportional to 7,578 and 12,111

Step by Step Solution

1. Step 1: Write the proportion equation
   7,578 : 12,111 = 12,111 : x
2. Step 2: Convert to fraction form
   7,578/12,111 = 12,111/x
3. Step 3: Cross multiply
   7,578x = 12,111 × 12,111
4. Step 4: Simplify right side
   7,578x = 146,676,321
5. Step 5: Solve for x
   x = 146,676,321/7,578
6. Step 6: Final answer
   x = 19,355.55