Finding the Third Proportional to 858 and 1,153.50

Step by Step Solution

1. Step 1: Write the proportion equation
   858 : 1,153.50 = 1,153.50 : x
2. Step 2: Convert to fraction form
   858/1,153.50 = 1,153.50/x
3. Step 3: Cross multiply
   858x = 1,153.50 × 1,153.50
4. Step 4: Simplify right side
   858x = 1,330,562.25
5. Step 5: Solve for x
   x = 1,330,562.25/858
6. Step 6: Final answer
   x = 1,550.77