3. From generation to generation, the mean age when smokers first start to smoke varies. However, the standard deviation of that age remains constant of around 2.1 years. A survey of 40 smokers of this generation was done to see if the mean starting age is at least 19. The sample mean was 18.1 with a sample standard deviation of 1.3. Do the data support the claim at the 5% level? (justify your answer by hypothesis testing) 4. The mean number of sick days an employee takes per year is believed to be about ten. Members of a personnel department do not believe this figure. They randomly survey eight employees. The number of sick days they took for the past year are as follows: 12, 4, 15, 3, 11, 8, 6, 8. Let x be the number of sick days they took for the past year. Should the personnel team believe that the mean number is ten? 5. The student academic group on a college campus claims that freshman students study at least 3 hours per day, on average. One Introduction to Statistics class was skeptical. The class took a random sample of 30 freshman students and found a mean study time of 140 minutes with a standard deviation of 45 minutes. At a = 0.05 level, is the student academic group's claim correct