Finding the Third Proportional to 251.50 and 498.88

Step by Step Solution

1. Step 1: Write the proportion equation
   251.50 : 498.88 = 498.88 : x
2. Step 2: Convert to fraction form
   251.50/498.88 = 498.88/x
3. Step 3: Cross multiply
   251.50x = 498.88 × 498.88
4. Step 4: Simplify right side
   251.50x = 248,876.27
5. Step 5: Solve for x
   x = 248,876.27/251.50
6. Step 6: Final answer
   x = 989.57