A die is thrown two times. It is found that the sum of the appeared numbers is 6. Find the conditional that the number 4 appeared at least one time.
Let the mean and variance of 7 observations 2, 4, 10, x, 12, 14, y, where x>y, be 8 and 16 respectively. Two numbers are chosen from \(\{1, 2, 3, x-4, y, 5\}\) one after another without replacement, then the probability, that the smaller number among the two chosen numbers is less than 4, is:
If the mean and the variance of the data 
are $\mu$ and 19 respectively, then the value of $\lambda + \mu$ is