If `bar X_1 and bar X_2` are the means of two series such that `bar X_1 lt bar X_2 and bar X` is the mean of the combined series, then

The vectors bar X and bar Y satisfy the equations 2bar X =bar p,bar X+2bar Y =bar q where bar p=bar i+bar j and bar q=bar i-bar j. If theta is the angle between bar X and bar Y then

Observe the following statements : (A) : 10 is the mean of a set of 7 obervations and 5 is the mean of a set of 3 observations. The mean of a combined set is 9. (R ) : If bar(x)_(i)(i = 1,2,…,k) are the means of k - series n_(i)(I = 1,2,3,…,k) respectively, then the combined or composite mean is bar(x) = (n_(1)bar(x)_(1) + n_(2) bar(x)_(2) + ...+ n_(k)bar(x_(k)))/(n_(1)+n_(2)+...+n_(k))

Observe the following statements : (A) : 10 is the mean of a set of 7 obervations and 5 is the mean of a set of 3 observations. The mean of a combined set is 9. (R ) : If bar(x)_(i)(i = 1,2,…,k) are the means of k - series n_(i)(I = 1,2,3,…,k) respectively, then the combined or composite mean is bar(x) = (n_(1)bar(x)_(1) + n_(2) bar(x)_(2) + ...+ n_(k)bar(x_(k)))/(n_(1)+n_(2)+...+n_(k))

If the mean of the set of numbers x_(1),x_(2),...x_(n) is bar(x), then the mean of the numbers x_(i)+2i,1<=i<=n is

The arithmetic mean of a set of observations is bar(X) . If each observation is divided by alpha and then is increased by 10, then the mean of the new series is

The arithmetic mean of a set of observations is bar(X) . If each observation is divided by alpha and then is increased by 10, then the mean of the new series is

The mean of the series x_(1),x_(2),...x_(n) is bar(X). If x_(2) is replaced by lambda then the new mean is