A car travels at an average speed of 48 miles per hour. How long it take to travel 156 miles

In the diagram of circle o, what is the measure of zabc?

If value of cos330° is √3/2 then find tan165°.

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