Finding the Third Proportional to 690 and 1,041.38

Step by Step Solution

1. Step 1: Write the proportion equation
   690 : 1,041.38 = 1,041.38 : x
2. Step 2: Convert to fraction form
   690/1,041.38 = 1,041.38/x
3. Step 3: Cross multiply
   690x = 1,041.38 × 1,041.38
4. Step 4: Simplify right side
   690x = 1,084,461.89
5. Step 5: Solve for x
   x = 1,084,461.89/690
6. Step 6: Final answer
   x = 1,571.68