Paul says that (3.14 x 10^5) + (2.53 x 10^4) = 5.67 x 10^5. Is Paul correct? i need a explaining

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?