A manufacturer wants to increase the shelf life of a line of cake mixes. Past records indicate that the average shelf life of the mix is 216 day After a revised mix has been developed, a sample of nine boxes of cake mix gave these shelf lives in days): 215, 217, 218, 219, 216, 217, 217, 218, ac 218. Using a -0.025, has the shelf life of the cake mix increased? Multiple Choice Yes, because computed is greater than the critical value Yes, because computed is less than the critical value. No, because computed eles in the region of acceptance, No, because 217.22 is quite close to 216