2. (25 points) 619 Students from grade 11 and grade 12 of Yorktown School are randomly selected. Selected are asked the question Do you own a cell phone? Following contin- gency table gives information on their response:

Do you own a cell phone?

Yes No Total

Grade

12 77

11 16 Total 93

404 481 122 138 526 619

(1) (12.5 points) What is the probability that selected student is from Grade 11" and does not own a cell phone"?

(2) (12.5 points) What is the probability that selected student is from Grade 11" given the information that the student owns a cell phone"?