Finding the Third Proportional to 128,220 and 199,051.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,220 : 199,051.50 = 199,051.50 : x
2. Step 2: Convert to fraction form
   128,220/199,051.50 = 199,051.50/x
3. Step 3: Cross multiply
   128,220x = 199,051.50 × 199,051.50
4. Step 4: Simplify right side
   128,220x = 39,621,499,652.25
5. Step 5: Solve for x
   x = 39,621,499,652.25/128,220
6. Step 6: Final answer
   x = 309,011.85