If the total number of observations is `20,sumx_i = 1000 and sum x_i^2 = 84000`, then what is the variance of the distribution?

If the total number of observations is 20,sum x_(i)=1000 and sum x_(i)^(2)=84000, then what is the variance of the distribution?

What is the amount of number of observations is barx=20 and sumx=500

The variance of 20 observation is 5. If each observation is multiplied by 2, then what is the new variance of the resulting observation?

The variance of 20 observation is 5. If each observation is multiplied by 2, then what is the new variance of the resulting observation?

The variance of 20 observation is 5. If each observation is multiplied by 3, then what is the new variance of the resulting observation?

The distributions X and Y with total number of observations 36 and 64, and mean 4 and 3 respectively are combined. What is the mean of the resulting distribution X + Y?