Finding the Third Proportional to 645,390 and 1,418,178

Step by Step Solution

1. Step 1: Write the proportion equation
   645,390 : 1,418,178 = 1,418,178 : x
2. Step 2: Convert to fraction form
   645,390/1,418,178 = 1,418,178/x
3. Step 3: Cross multiply
   645,390x = 1,418,178 × 1,418,178
4. Step 4: Simplify right side
   645,390x = 2,011,228,839,684
5. Step 5: Solve for x
   x = 2,011,228,839,684/645,390
6. Step 6: Final answer
   x = 3,116,299.97