Which of the following is not an observation about critical values? choose the correct answer below. a.a critical value is the number on the borderline separating sample statistics that are likely to occur from those that are unlikely to occur. b.the number z subscript alpha divided by 2is a critical value that corresponds to an area of 1minusalpha divided by 2to its left. c.a critical value is the area in the right-tail region of the standard normal curve. d.the number z subscript alpha divided by 2is a critical value that is a z score with the property that it separates an area of alpha divided by 2in the right tail of the standard normal distribution.