Finding the Third Proportional to 16,918.88 and 21,991.50

Step by Step Solution

1. Step 1: Write the proportion equation
   16,918.88 : 21,991.50 = 21,991.50 : x
2. Step 2: Convert to fraction form
   16,918.88/21,991.50 = 21,991.50/x
3. Step 3: Cross multiply
   16,918.88x = 21,991.50 × 21,991.50
4. Step 4: Simplify right side
   16,918.88x = 483,626,072.25
5. Step 5: Solve for x
   x = 483,626,072.25/16,918.88
6. Step 6: Final answer
   x = 28,585.00