Finding the Third Proportional to 857 and 1,379.50

Step by Step Solution

1. Step 1: Write the proportion equation
   857 : 1,379.50 = 1,379.50 : x
2. Step 2: Convert to fraction form
   857/1,379.50 = 1,379.50/x
3. Step 3: Cross multiply
   857x = 1,379.50 × 1,379.50
4. Step 4: Simplify right side
   857x = 1,903,020.25
5. Step 5: Solve for x
   x = 1,903,020.25/857
6. Step 6: Final answer
   x = 2,220.56