Finding the Third Proportional to 278.50 and 379.25

Step by Step Solution

1. Step 1: Write the proportion equation
   278.50 : 379.25 = 379.25 : x
2. Step 2: Convert to fraction form
   278.50/379.25 = 379.25/x
3. Step 3: Cross multiply
   278.50x = 379.25 × 379.25
4. Step 4: Simplify right side
   278.50x = 143,830.56
5. Step 5: Solve for x
   x = 143,830.56/278.50
6. Step 6: Final answer
   x = 516.45