Finding the Third Proportional to 670.78 and 889.31

Step by Step Solution

1. Step 1: Write the proportion equation
   670.78 : 889.31 = 889.31 : x
2. Step 2: Convert to fraction form
   670.78/889.31 = 889.31/x
3. Step 3: Cross multiply
   670.78x = 889.31 × 889.31
4. Step 4: Simplify right side
   670.78x = 790,876.72
5. Step 5: Solve for x
   x = 790,876.72/670.78
6. Step 6: Final answer
   x = 1,179.04