Finding the Third Proportional to 1,478.25 and 3,421.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,478.25 : 3,421.69 = 3,421.69 : x
2. Step 2: Convert to fraction form
   1,478.25/3,421.69 = 3,421.69/x
3. Step 3: Cross multiply
   1,478.25x = 3,421.69 × 3,421.69
4. Step 4: Simplify right side
   1,478.25x = 11,707,945.35
5. Step 5: Solve for x
   x = 11,707,945.35/1,478.25
6. Step 6: Final answer
   x = 7,920.14