we calculate standard deviation to find the avg of the difference of all values from mean.,
What is mean deviation and why is quartile deviation better than mean deviation?
mean deviation =(4/5)quartile deviation
It is not possible to answer without any information on the spread (range, inter-quartile range, mean absolute deviation, standard deviation or variance).
If this is the only information you have, the answer would be somewhere around 125. Usually, you would find the third quartile by first finding the median. Then find the median of all of the numbers between the median and the largest number, which is the third quartile.
Standard error, standard deviation, variance, range, inter-quartile range as well as measures based on other percentiles.
It is mean + 2*standard deviation.
When using the mean: the variance or standard deviation. When using the median: the range or inter-quartile range.
to calculate standard deviation using pointers
There is no such thing. Maybe your professor meant , Standard Deviation, The Mean. (2 different things.)
Mean 0, standard deviation 1.