Finding the Third Proportional to 864 and 1,291.50

Step by Step Solution

1. Step 1: Write the proportion equation
   864 : 1,291.50 = 1,291.50 : x
2. Step 2: Convert to fraction form
   864/1,291.50 = 1,291.50/x
3. Step 3: Cross multiply
   864x = 1,291.50 × 1,291.50
4. Step 4: Simplify right side
   864x = 1,667,972.25
5. Step 5: Solve for x
   x = 1,667,972.25/864
6. Step 6: Final answer
   x = 1,930.52