The variance of series `a, a+d, a+2d,...........,a+2nd` is

Mean deviation of the series a,a+d,a+2d,......,a+2nd from its mean is (a) ((n+1)d)/((2n+1))( b )(nd)/(2n+1) (c) ((2n+1)d)/(n(n+1)) (d) (n(n+1)d)/(2n+1)

The mean deviation of the series a , a+d , a+2d ,.....,a+2nd from its mean is (a) ((n+1)d)/(2n+1) (b) (n d)/(2n+1) (c) (n(n+1)d)/(2n+1) (d) ((2n+1)d)/(n(n+1))

The mean deviation of the series a , a+d , a+2d ,.....,a+2n from its mean is (a) ((n+1)d)/(2n+1) (b) (n d)/(2n+1) (c) (n(n+1)d)/(2n+1) (d) ((2n+1)d)/(n(n+1))

The mean of the series a, a + d, a + 2d, …, a + 2 nd, is

The mean deviation of the series a, a+d, a+2d, . . . , a+2n from its mean is -

mean of the series a , a+d, a+2d,……………, a + 2nd is …..

The mean of the series a,a+d, a+2d,…,a+2nd is

Find the mean deviation from the mean of the A.P., a,a+d, a+2d, .........,a+2nd.

Find the mean deviation from the mean of the A.P., a,a+d, a+2d, .........,a+2nd.