Our environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 6.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 26 samples is 6.2 ppm with a variance of 0.36. assume the population is normally distributed. a level of significance of 0.05 will be used. make the decision to reject or fail to reject the null hypothesis.