Finding the Third Proportional to 9,991 and 21,440

Step by Step Solution

1. Step 1: Write the proportion equation
   9,991 : 21,440 = 21,440 : x
2. Step 2: Convert to fraction form
   9,991/21,440 = 21,440/x
3. Step 3: Cross multiply
   9,991x = 21,440 × 21,440
4. Step 4: Simplify right side
   9,991x = 459,673,600
5. Step 5: Solve for x
   x = 459,673,600/9,991
6. Step 6: Final answer
   x = 46,008.77