An article gave the following observations on maximum concrete pressure (kam2]. 33.3 41.8 37.4 40.3 36.7 39.2 35.2 41.9 36.0 35.2 36.8 38.9 35.9 35.3 4-0.1 [a] Is it plausible that this sample was selected from a normal population distribution? '3' Using a normal probability plot, we ascertain that it is plausible that this sample was taken from a normal population distribution. 7"- Using a normal probability plot, we ascertain that it is not plausible that this sample was taken from a normal population distribution. (:3 Because of the number of observations, we ascertain that it is not plausible that this sample was taken from a normal population distribution. .:_-. Because of the number of observations, we ascertain that it is plausible that this sample was taken from a normal population distribution. (b) Calculate an upper confidence bound with condence level 95% for the population standard deviation of maximum pressure. {Round your answer to three decimal places.) Z You may need to use the appropriate table in the Appendix of Tables to answer this