mean +- 2.5 sd is from 12.5 to 27.5
Only number outside this range is 12. Hence, A.
I simply guessed through this question thought the value with max diff from mean is the answr
Can u tell me how u got the values 12.5 and 27.5
spriya, read the question this way -->
If a certain sample of data has a mean of 20 and a standard deviation of 3, which of the following values is more than 2.5 (standard deviations)
from the mean?
I hope now you will get how we get the answer