The arithmetic mean of set M is zero. If N = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of M consisting of all those elements in M which are more than two but less than three standard deviations away from the arithmetic mean of M, what could be equal to the standard deviation of M?	Options: A) 0.54 B) 0.77 C) 0.82 D) 0.97 E) 1.62
This is a fairly straightforward question that can be solved quickly by just applying the options   We are provided with Mean, m= 0   and N = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of M   N consists of all those elements in M that are more than 2 but less than 3 MDs away from the arithmetic mean of M   If an element is 1 MD away from the mean, we can write it as either m + MD or m - MD   Similarly, if an element is 2 MDs away from the mean, we can write it as either m + 2*MD or m - 2*MD   So, if these elements lie within 2 and 3 MDs of mean, m=0   we can find which one of these values of MD satisfies each value within N   Only MD = 0.77 does   Answer : 0.77
<result>B</result>
The arithmetic mean of set M is zero. If N = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of M consisting of all those elements in M which are more than two but less than three standard deviations away from the arithmetic mean of M, what could be equal to the standard deviation of M?