Finding the Third Proportional to 393.50 and 579.50

Step by Step Solution

1. Step 1: Write the proportion equation
   393.50 : 579.50 = 579.50 : x
2. Step 2: Convert to fraction form
   393.50/579.50 = 579.50/x
3. Step 3: Cross multiply
   393.50x = 579.50 × 579.50
4. Step 4: Simplify right side
   393.50x = 335,820.25
5. Step 5: Solve for x
   x = 335,820.25/393.50
6. Step 6: Final answer
   x = 853.42