Finding the Third Proportional to 128,779.50 and 196,999.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,779.50 : 196,999.50 = 196,999.50 : x
2. Step 2: Convert to fraction form
   128,779.50/196,999.50 = 196,999.50/x
3. Step 3: Cross multiply
   128,779.50x = 196,999.50 × 196,999.50
4. Step 4: Simplify right side
   128,779.50x = 38,808,803,000.25
5. Step 5: Solve for x
   x = 38,808,803,000.25/128,779.50
6. Step 6: Final answer
   x = 301,358.55