Exer. 7980: If I(t) is the current (in amperes) in an alternating current circuit at time t (in seconds), find the smallest exact value of t for which I(t) k.

● Data ○ The facts and figures collected,analyzed, and summarized for presentation and interpretation. ○ cases are the objects described by a set of data. ○ label is a special variable used in some data sets to distinguish the different cases. ○ variable is any characteristic of an individual or object. ■ Categorical variable (factor)a case into one of several groups or categories ■ Quantitative variable numerical values ● Discrete countable set of values ● Continuous values within some interval ● Types of data ○ P