Graphs express the relationship between two variables by mapping one variable along the x-axis and the other variable along the y-axis. Identify each component of this graph as either a variable or a level of a variable from the Twitter study. variable(s) level(s) of a variable 5.4, 5.6, 5.8, 6.0 Press Space to open days of the week Press Space to open midnight, noon Press Space to open percent of positive-emotion words Press Space to open Sunday, Monday, Tuesday Press Space to open time of day