Finding the Third Proportional to 1,155 and 1,386

Step by Step Solution

1. Step 1: Write the proportion equation
   1,155 : 1,386 = 1,386 : x
2. Step 2: Convert to fraction form
   1,155/1,386 = 1,386/x
3. Step 3: Cross multiply
   1,155x = 1,386 × 1,386
4. Step 4: Simplify right side
   1,155x = 1,920,996
5. Step 5: Solve for x
   x = 1,920,996/1,155
6. Step 6: Final answer
   x = 1,663.20