Finding the Third Proportional to 856.50 and 2,116.50

Step by Step Solution

1. Step 1: Write the proportion equation
   856.50 : 2,116.50 = 2,116.50 : x
2. Step 2: Convert to fraction form
   856.50/2,116.50 = 2,116.50/x
3. Step 3: Cross multiply
   856.50x = 2,116.50 × 2,116.50
4. Step 4: Simplify right side
   856.50x = 4,479,572.25
5. Step 5: Solve for x
   x = 4,479,572.25/856.50
6. Step 6: Final answer
   x = 5,230.09