Abox contains 8 green and 4 blue marbles. two marbles are selected (at once with no replacement). find the expected number of green marbles among the selected ones.

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

This stem-and-leaf plot represents the heights of the students on ralph's basketball team. one student's height is missing from the plot. if the mean height of all the students on the team is 61 inches, what is the missing height? a. 55 in. b. 59 in. c. 61 in. d. 65 in.

Elizabeth is using a sample to study american alligators. she plots the lengths of their tails against their total lengths to find the relationship between the two attributes. which point is an outlier in this data set?