Finding the Third Proportional to 1,389.50 and 2,089.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.50 : 2,089.31 = 2,089.31 : x
2. Step 2: Convert to fraction form
   1,389.50/2,089.31 = 2,089.31/x
3. Step 3: Cross multiply
   1,389.50x = 2,089.31 × 2,089.31
4. Step 4: Simplify right side
   1,389.50x = 4,365,226.72
5. Step 5: Solve for x
   x = 4,365,226.72/1,389.50
6. Step 6: Final answer
   x = 3,141.58