Finding the Third Proportional to 21,191 and 31,129.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,191 : 31,129.50 = 31,129.50 : x
2. Step 2: Convert to fraction form
   21,191/31,129.50 = 31,129.50/x
3. Step 3: Cross multiply
   21,191x = 31,129.50 × 31,129.50
4. Step 4: Simplify right side
   21,191x = 969,045,770.25
5. Step 5: Solve for x
   x = 969,045,770.25/21,191
6. Step 6: Final answer
   x = 45,729.12