Bob takes the subway to work and uses an escalator at the railway station. if bob runs up 8 steps of the escalator, then it takes him 46.5 seconds to reach the top of the escalator. if he runs up 13 steps of the escalator, then it takes him only 39.0 seconds to reach the top. how many seconds would it take bob to reach the top if he did not run up any steps of the escalator?

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