Finding the Third Proportional to 265.50 and 390.75

Step by Step Solution

1. Step 1: Write the proportion equation
   265.50 : 390.75 = 390.75 : x
2. Step 2: Convert to fraction form
   265.50/390.75 = 390.75/x
3. Step 3: Cross multiply
   265.50x = 390.75 × 390.75
4. Step 4: Simplify right side
   265.50x = 152,685.56
5. Step 5: Solve for x
   x = 152,685.56/265.50
6. Step 6: Final answer
   x = 575.09