Finding the Third Proportional to 1,390.88 and 2,166.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.88 : 2,166.09 = 2,166.09 : x
2. Step 2: Convert to fraction form
   1,390.88/2,166.09 = 2,166.09/x
3. Step 3: Cross multiply
   1,390.88x = 2,166.09 × 2,166.09
4. Step 4: Simplify right side
   1,390.88x = 4,691,962.13
5. Step 5: Solve for x
   x = 4,691,962.13/1,390.88
6. Step 6: Final answer
   x = 3,373.39