The following are 10 measurements of the specific gravity y of the same sample of an alloy:

(a) Calculate the average y and standard deviations for this sample of n = 10 observations.
(b) Plot the residuals y- y in time order.
(c) It is proposed. to make an analysis on the assumption that the 10 observations are a random sample from a normal distribution. Do you have any doubts about the validity of this assumption?