Please help!! I'm very confused

Alogical argument that is presented in graphical form using boxes and arrows is called?

Aretha wanted to gather data about the cost of local bowling leagues in her area. she plotted the data and determined that the average bowling league costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 15x + 20. identify and interpret the y-intercept in this model. the y-intercept is 20. this is the cost per month. the y-intercept is 20. this is the cost of registration. the y-intercept is 15. this is the cost of registration. the y-intercept is 15. this is the cost per month.

Alex measured the length of an item to be 3.7 cm. the actual length is 3.5 cm. what is alex’s percent error?