A linear regression line has an equation of the form Y = bx+a, where x is the explanatory variable and Y is the dependent variable. The slope of the line is b, and a is the intercept (the value of y when x = 0).
The given equation is
![y=(21)/(5) x+98](https://img.qammunity.org/2019/formulas/mathematics/college/hix18o6c681iw29h97t9cvi15e3bzhnkoh.png)
The slope of the line is
![(21)/(5)](https://img.qammunity.org/2019/formulas/mathematics/college/no477ki7jynvlwm95g9t6o5uwbc802prkj.png)
The slope represents
For every 21 minutes that people spend using their cell phone, the number of texts they send increases by 5.