Finding the Third Proportional to 190.50 and 278.50

Step by Step Solution

1. Step 1: Write the proportion equation
   190.50 : 278.50 = 278.50 : x
2. Step 2: Convert to fraction form
   190.50/278.50 = 278.50/x
3. Step 3: Cross multiply
   190.50x = 278.50 × 278.50
4. Step 4: Simplify right side
   190.50x = 77,562.25
5. Step 5: Solve for x
   x = 77,562.25/190.50
6. Step 6: Final answer
   x = 407.15