plz use calculator and not tables

19. Hours Online: rI'he number of hours spent online by college students is claimed to be 22.5 hours per week with a stande deviation of 2.1 hours. (a) Suppose we randomly select 50 college students, what is the probability that the mean number of hours online is greater than 2155:: (b) Suppose I survey the 50 game programming students and the mean number of hours spent online is 25 hours per week. Is this unusual? Why or why not