Finding the Third Proportional to 388.69 and 510.75

Step by Step Solution

1. Step 1: Write the proportion equation
   388.69 : 510.75 = 510.75 : x
2. Step 2: Convert to fraction form
   388.69/510.75 = 510.75/x
3. Step 3: Cross multiply
   388.69x = 510.75 × 510.75
4. Step 4: Simplify right side
   388.69x = 260,865.56
5. Step 5: Solve for x
   x = 260,865.56/388.69
6. Step 6: Final answer
   x = 671.14