Finding the Third Proportional to 145,400 and 213,300

Step by Step Solution

1. Step 1: Write the proportion equation
   145,400 : 213,300 = 213,300 : x
2. Step 2: Convert to fraction form
   145,400/213,300 = 213,300/x
3. Step 3: Cross multiply
   145,400x = 213,300 × 213,300
4. Step 4: Simplify right side
   145,400x = 45,496,890,000
5. Step 5: Solve for x
   x = 45,496,890,000/145,400
6. Step 6: Final answer
   x = 312,908.46