Finding the Third Proportional to 21,915 and 31,009.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,915 : 31,009.50 = 31,009.50 : x
2. Step 2: Convert to fraction form
   21,915/31,009.50 = 31,009.50/x
3. Step 3: Cross multiply
   21,915x = 31,009.50 × 31,009.50
4. Step 4: Simplify right side
   21,915x = 961,589,090.25
5. Step 5: Solve for x
   x = 961,589,090.25/21,915
6. Step 6: Final answer
   x = 43,878.12