You are a school photographer taking individual and class pictures for 2 classes of 21 students each. on average, each individual picture takes 3 minutes and a class picture takes 10 minutes. about how long should it take you to take all of the pictures?

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