Classify each number according to its value. 4.2 × 10-6
2.1 × 10-3
3.1 × 10-2
3.2 × 10-5
3.5 × 10-4
5.8 × 10-3
5.2 × 10-4

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?