Finding the Third Proportional to 12,985 and 20,146.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,985 : 20,146.50 = 20,146.50 : x
2. Step 2: Convert to fraction form
   12,985/20,146.50 = 20,146.50/x
3. Step 3: Cross multiply
   12,985x = 20,146.50 × 20,146.50
4. Step 4: Simplify right side
   12,985x = 405,881,462.25
5. Step 5: Solve for x
   x = 405,881,462.25/12,985
6. Step 6: Final answer
   x = 31,257.72