Finding the Third Proportional to 128,125.50 and 191,139

Step by Step Solution

1. Step 1: Write the proportion equation
   128,125.50 : 191,139 = 191,139 : x
2. Step 2: Convert to fraction form
   128,125.50/191,139 = 191,139/x
3. Step 3: Cross multiply
   128,125.50x = 191,139 × 191,139
4. Step 4: Simplify right side
   128,125.50x = 36,534,117,321
5. Step 5: Solve for x
   x = 36,534,117,321/128,125.50
6. Step 6: Final answer
   x = 285,143.22