Finding the Third Proportional to 143,210 and 210,428

Step by Step Solution

1. Step 1: Write the proportion equation
   143,210 : 210,428 = 210,428 : x
2. Step 2: Convert to fraction form
   143,210/210,428 = 210,428/x
3. Step 3: Cross multiply
   143,210x = 210,428 × 210,428
4. Step 4: Simplify right side
   143,210x = 44,279,943,184
5. Step 5: Solve for x
   x = 44,279,943,184/143,210
6. Step 6: Final answer
   x = 309,195.89