Finding the Third Proportional to 5,458 and 12,819

Step by Step Solution

1. Step 1: Write the proportion equation
   5,458 : 12,819 = 12,819 : x
2. Step 2: Convert to fraction form
   5,458/12,819 = 12,819/x
3. Step 3: Cross multiply
   5,458x = 12,819 × 12,819
4. Step 4: Simplify right side
   5,458x = 164,326,761
5. Step 5: Solve for x
   x = 164,326,761/5,458
6. Step 6: Final answer
   x = 30,107.50