Finding the Third Proportional to 1,389 and 1,990.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389 : 1,990.50 = 1,990.50 : x
2. Step 2: Convert to fraction form
   1,389/1,990.50 = 1,990.50/x
3. Step 3: Cross multiply
   1,389x = 1,990.50 × 1,990.50
4. Step 4: Simplify right side
   1,389x = 3,962,090.25
5. Step 5: Solve for x
   x = 3,962,090.25/1,389
6. Step 6: Final answer
   x = 2,852.48