Finding the Third Proportional to 11,139 and 17,128.50

Step by Step Solution

1. Step 1: Write the proportion equation
   11,139 : 17,128.50 = 17,128.50 : x
2. Step 2: Convert to fraction form
   11,139/17,128.50 = 17,128.50/x
3. Step 3: Cross multiply
   11,139x = 17,128.50 × 17,128.50
4. Step 4: Simplify right side
   11,139x = 293,385,512.25
5. Step 5: Solve for x
   x = 293,385,512.25/11,139
6. Step 6: Final answer
   x = 26,338.59