5.13 Identify hypotheses, Part I. Write the null and alternative hypotheses in words and then symbols foreach of the following situations.(a) A tutoring company would like to understand if most students tend to improve their grades (or not)after they use their services. They sample 200 of the students who used their service in the past yearand ask them if their grades have improved or declined from the previous year.(b) Employers at a firm are worried about the effect of March Madness, a basketball championship held eachspring in the US, on employee productivity. They estimate that on a regular business day employeesspend on average 15 minutes of company time checking personal email, making personal phone calls, etc. They also collect data on how much company time employees spend on such non-business activitiesduring March Madness. They want to determine if these data provide convincing evidence that employeeproductivity changed during March Madness.

Apoll is being conducted at a mall nothingto obtain a sample of the population of an entire country. what is the frame for this type of​ sampling? who would be excluded from the survey and how might this affect the results of the​ survey? what is the frame for this type of​ sampling? a. the frame is people who need new clothes. b. the frame is people who shop at the mall. c. the frame is people who like to shop. d. the frame is the entire population of the country. who would be excluded from the survey and how might this affect the results of the​ survey? a. any person that does not need new clothes is excluded. this could result in sampling bias due to undercoverage. b. any person who does not shop at the mall is excluded. this could result in sampling bias due to undercoverage. c. any person who does not shop at the mall is excluded. this could result in nonresponse bias due to people not participating in the poll. d. there is nobody that is being excluded from the survey.