Do not tell me the answer to number 8,just tell me how to do it

How do you graph linear equation x+y=4

1yd 1 ft = 1 1/12 1 1/3 1 1/2 1 1/6

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