Suppose five 6.0 oz tubes of toothpaste of a particular brand are randomly selected and squeezed until no more toothpaste will come out. then each tube is cut open and the amount remaining is weighed, resulting in the following data: "0.51, 0.61, 0.43, 0.5, 0.35". does it appear that the true average amount left is less than 10% of the advertised net contents? check the validity of any assumptions necessary for testing the appropriate hypotheses.

(a) the sample was randomly selected and the normal probability plot is not acceptably nonlinear
(b) the sample was selected to represent a range of results and the normal probability plot is not acceptably linear.
(c) the sample was randomly selected and the normal probability plot is acceptably linear
(d) the sample was selected to represent a range of results and the normal probability plot is not acceptably nonlinear