Finding the Third Proportional to 666.56 and 779.06

Step by Step Solution

1. Step 1: Write the proportion equation
   666.56 : 779.06 = 779.06 : x
2. Step 2: Convert to fraction form
   666.56/779.06 = 779.06/x
3. Step 3: Cross multiply
   666.56x = 779.06 × 779.06
4. Step 4: Simplify right side
   666.56x = 606,938.38
5. Step 5: Solve for x
   x = 606,938.38/666.56
6. Step 6: Final answer
   x = 910.55