Researchers want to determine the percentage of students who own iPhones and Android cell phones. They go to a popular spot on campus and ask first 100 students who pass what type of cell phone they own. What type of sampling method is this

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?