Finding the Third Proportional to 860 and 1,289.50

Step by Step Solution

1. Step 1: Write the proportion equation
   860 : 1,289.50 = 1,289.50 : x
2. Step 2: Convert to fraction form
   860/1,289.50 = 1,289.50/x
3. Step 3: Cross multiply
   860x = 1,289.50 × 1,289.50
4. Step 4: Simplify right side
   860x = 1,662,810.25
5. Step 5: Solve for x
   x = 1,662,810.25/860
6. Step 6: Final answer
   x = 1,933.50