Finding the Third Proportional to 666 and 1,090.50

Step by Step Solution

1. Step 1: Write the proportion equation
   666 : 1,090.50 = 1,090.50 : x
2. Step 2: Convert to fraction form
   666/1,090.50 = 1,090.50/x
3. Step 3: Cross multiply
   666x = 1,090.50 × 1,090.50
4. Step 4: Simplify right side
   666x = 1,189,190.25
5. Step 5: Solve for x
   x = 1,189,190.25/666
6. Step 6: Final answer
   x = 1,785.57