Finding the Third Proportional to 2,487.80 and 4,128.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,487.80 : 4,128.89 = 4,128.89 : x
2. Step 2: Convert to fraction form
   2,487.80/4,128.89 = 4,128.89/x
3. Step 3: Cross multiply
   2,487.80x = 4,128.89 × 4,128.89
4. Step 4: Simplify right side
   2,487.80x = 17,047,737.79
5. Step 5: Solve for x
   x = 17,047,737.79/2,487.80
6. Step 6: Final answer
   x = 6,852.54