Which line has a constant of proportionality between y and x of 5/4

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population,find the population standard deviation, o.79828588912497

The equation of a parabola is given. y=18x2+4x+20 what are the coordinates of the focus of the parabola?

Which of the following is the major negative aspect of crossover designs for research studies? a. prohibitive cost b. residual effects c-subject drepout d. incomplete randomization e. large sample size required