I know that it's a straight line because the equation is written in this format; y=mx+b (this is a linear equation meaning that it must be a straight line). In that equation, m is our slope and b is our y-intercept with this information. I know that the y-intercept is 2 since this equation is this y= –12x+2 (the 2 replaced the b which is our y-intercept). The line does not pass through the origin because its y-intercept is 2 which means it's impossible for the line to pass through the origin. (I hope this makes sense)
Yes, because the sample is random. If she had chosen the participants in any way other than randomly, it would not be representative of her entire school.
