Finding the Third Proportional to 18,321.19 and 19,981.69

Step by Step Solution

1. Step 1: Write the proportion equation
   18,321.19 : 19,981.69 = 19,981.69 : x
2. Step 2: Convert to fraction form
   18,321.19/19,981.69 = 19,981.69/x
3. Step 3: Cross multiply
   18,321.19x = 19,981.69 × 19,981.69
4. Step 4: Simplify right side
   18,321.19x = 399,267,835.35
5. Step 5: Solve for x
   x = 399,267,835.35/18,321.19
6. Step 6: Final answer
   x = 21,792.68