Specify and execute the following queries for the database in Exercise 5.16 using the RA interpreter. a. Retrieve the names of students who have enrolled in a course that uses a textbook published by Addison-Wesley-Longman. b. Retrieve the names of courses in which the textbook has been changed at least once. c. Retrieve the names of departments that adopt textbooks published by Addison-Wesley only. d. Retrieve the names of departments that adopt textbooks written by Navathe and published by Addison-Wesley. e. Retrieve the names of students who have never used a book (in a course) written by Navathe and published by Addison-Wesley

Researchers measured the data speeds for a particular smartphone carrier at 50 airports. the highest speed measured was 78.1 mbps. the complete list of 50 data speeds has a mean of x overbarequals16.11 mbps and a standard deviation of sequals18.65 mbps. a. what is the difference between carrier's highest data speed and the mean of all 50 data speeds? b. how many standard deviations is that [the difference found in part (a)]? c. convert the carrier's highest data speed to a z score. d. if we consider data speeds that convert to z scores between minus2 and 2 to be neither significantly low nor significantly high, is the carrier's highest data speed significant? a. the difference is nothing mbps.