a box contains 18 blue flashlights 3 red flashlights 7 silver flashlights ans 2 black flashlights. the flashlights are identical in size and shape. if one flashlight is chosen at random what is the probability that the flashlight will be either blue or black?

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