Finding the Third Proportional to 28 and 42.50

Step by Step Solution

1. Step 1: Write the proportion equation
   28 : 42.50 = 42.50 : x
2. Step 2: Convert to fraction form
   28/42.50 = 42.50/x
3. Step 3: Cross multiply
   28x = 42.50 × 42.50
4. Step 4: Simplify right side
   28x = 1,806.25
5. Step 5: Solve for x
   x = 1,806.25/28
6. Step 6: Final answer
   x = 64.51