A randomization distribution is created to test a null hypothesis that the slope of a regression line is zero. The randomization distribution of sample slopes follows a normal distribution, centered at zero, with a standard deviation of 2.5.
(a) Draw a rough sketch of this randomization distribution, including a scale for the horizontal axis.
(b) Under this normal distribution, how likely are we to see a sample slope above 3.0?
(c) Find the location of the 5%-tile in this normal distribution of sample slopes.