Finding the Third Proportional to 4,221 and 5,518.50

Step by Step Solution

1. Step 1: Write the proportion equation
   4,221 : 5,518.50 = 5,518.50 : x
2. Step 2: Convert to fraction form
   4,221/5,518.50 = 5,518.50/x
3. Step 3: Cross multiply
   4,221x = 5,518.50 × 5,518.50
4. Step 4: Simplify right side
   4,221x = 30,453,842.25
5. Step 5: Solve for x
   x = 30,453,842.25/4,221
6. Step 6: Final answer
   x = 7,214.84