State true or false.
(i) For all data, `\sum_{i=1}^n (x_i - \bar{x}) = 0`.
(ii) Mean and median of the following data are equal: 5, 3, 9, 6, 7.
(iii) If `n` is an odd number, then `(n+1)/2`-th term is the median.
(iv) If `n` is an even number, then average of `n/2` th and `(n/2-1)` th observation is the median of that data.
(v) Median of the data `2, 3, 9, 10, 9, 3, 9` is 10.
(vi) The median is always one of the numbers in a data.
(vii) An ogive is always a straight line graph.
(viii) Mode of the data `2, 3, 3, 2, 5, 2, 3, 6, 5` is 6.
(ix) There can be multiple modes for a given data set.
(x) There can be no mode for a given data set.