Finding the Third Proportional to 66.19 and 145.31

Step by Step Solution

1. Step 1: Write the proportion equation
   66.19 : 145.31 = 145.31 : x
2. Step 2: Convert to fraction form
   66.19/145.31 = 145.31/x
3. Step 3: Cross multiply
   66.19x = 145.31 × 145.31
4. Step 4: Simplify right side
   66.19x = 21,115.72
5. Step 5: Solve for x
   x = 21,115.72/66.19
6. Step 6: Final answer
   x = 319.03