Finding the Third Proportional to 196.59 and 287.91

Step by Step Solution

1. Step 1: Write the proportion equation
   196.59 : 287.91 = 287.91 : x
2. Step 2: Convert to fraction form
   196.59/287.91 = 287.91/x
3. Step 3: Cross multiply
   196.59x = 287.91 × 287.91
4. Step 4: Simplify right side
   196.59x = 82,890.01
5. Step 5: Solve for x
   x = 82,890.01/196.59
6. Step 6: Final answer
   x = 421.63