Finding the Third Proportional to 1,398.38 and 2,189.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.38 : 2,189.81 = 2,189.81 : x
2. Step 2: Convert to fraction form
   1,398.38/2,189.81 = 2,189.81/x
3. Step 3: Cross multiply
   1,398.38x = 2,189.81 × 2,189.81
4. Step 4: Simplify right side
   1,398.38x = 4,795,278.79
5. Step 5: Solve for x
   x = 4,795,278.79/1,398.38
6. Step 6: Final answer
   x = 3,429.18