There are 9 teams that are numbered respectively from 1 to 9. Each team member has the group number printed on his/her shirt and each team cannot have more team members then its number. Armen started to add up all the odd numbers he saw on the shirts and asked David to add up all the even ones. What is the greatest possible difference between David's results and Armen's result?

65% of students in your school participate in at least one after school activity. if there are 980 students in you school, how many do not participate in an after school activity?

At store a, erasers are sold individually. the cost y of x erasers is represented by the equation y=0.75x. the costs of erasers at store b are shown in the graph.

Abby is collecting rainfall data. she finds that one value of the data set is a high-value outlier. which statement must be true? abby will use a different formula for calculating the standard deviation. the outlier will increase the standard deviation of the data set. the spread of the graph of the data will not change. abby will not use the mean when calculating the standard deviation.