Finding the Third Proportional to 158,128.50 and 251,269.50

Step by Step Solution

1. Step 1: Write the proportion equation
   158,128.50 : 251,269.50 = 251,269.50 : x
2. Step 2: Convert to fraction form
   158,128.50/251,269.50 = 251,269.50/x
3. Step 3: Cross multiply
   158,128.50x = 251,269.50 × 251,269.50
4. Step 4: Simplify right side
   158,128.50x = 63,136,361,630.25
5. Step 5: Solve for x
   x = 63,136,361,630.25/158,128.50
6. Step 6: Final answer
   x = 399,272.50