Apie is cut into 9 equal pieces. if all but 3 pieces are eaten, how of the pie remains?

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

How can you find the mean absolute deviation (mad) for this set of data?

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