Finding the Third Proportional to 4,218 and 9,131.50

Step by Step Solution

1. Step 1: Write the proportion equation
   4,218 : 9,131.50 = 9,131.50 : x
2. Step 2: Convert to fraction form
   4,218/9,131.50 = 9,131.50/x
3. Step 3: Cross multiply
   4,218x = 9,131.50 × 9,131.50
4. Step 4: Simplify right side
   4,218x = 83,384,292.25
5. Step 5: Solve for x
   x = 83,384,292.25/4,218
6. Step 6: Final answer
   x = 19,768.68