Finding the Third Proportional to 143,196 and 309,990

Step by Step Solution

1. Step 1: Write the proportion equation
   143,196 : 309,990 = 309,990 : x
2. Step 2: Convert to fraction form
   143,196/309,990 = 309,990/x
3. Step 3: Cross multiply
   143,196x = 309,990 × 309,990
4. Step 4: Simplify right side
   143,196x = 96,093,800,100
5. Step 5: Solve for x
   x = 96,093,800,100/143,196
6. Step 6: Final answer
   x = 671,064.83