2x+y=40 kx+2y=80 A system of equations is shown, where k is a constant. If the lines represented by the equations in the system are graphed in the xy-plane, for what value of k would the lines coincide?

A. -4

B. 1

C. 2

D. -4

Ur environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 4.04.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 2525 samples is 4.44.4 ppm with a standard deviation of 0.80.8. assume the population is normally distributed. a level of significance of 0.020.02 will be used. make the decision to reject or fail to reject the null hypothesis. answer tables