Global use of cell phones grew rapidly between 1989 and 2000. below is a scatterplot of the percentage of people in the world who are cell phone subscribers versus year for this time interval, along with the residual plot from a linear regression analysis. (a) is a linear model appropriate for these data? justify your answer. (b) below is a scatterplot of the natural logarithm of cell phone subscribers vs. year. this relationship is clearly more linear that the one above. does this suggest that the relationship between cell phone subscribers and year can be modeled by an exponential function or by a power function? explain. (c) computer output from the regression of ln (cell phone subscribers) vs. year is given below. use it to predict the percentage of people in the world who were cell phone subscribers in 2005. (d) comment on the reliability of this prediction.

Suppose that fizzo and pop hop are the only two firms that sell orange soda. the following payoff matrix shows the profit (in millions of dollars) each company will earn depending on whether or not it advertises: pop hopadvertise doesn’t advertisefizzo advertise 10, 10 18, 2doesn’t advertise 2, 18 11, 11for example, the upper right cell shows that if fizzo advertises and pop hop doesn't advertise, fizzo will make a profit of $18 million, and pop hop will make a profit of $2 million. assume this is a simultaneous game and that fizzo and pop hop are both profit-maximizing firms.if fizzo decides to advertise, it will earn a profit if pop hop advertises and a profit if pop hop does not advertise.if fizzo decides not to advertise, it will earn a profit if pop hop advertises and a profit if pop hop does not advertise.if pop hop advertises, fizzo makes a higher profit if it chooses (not to advertise, to .if pop hop doesn't advertise, fizzo makes a higher profit if it chooses (not to advertise, to . suppose that both firms start off not advertising. if the firms act independently, what strategies will they end up choosing? fizzo will choose to advertise and pop hop will choose not to advertise.both firms will choose to advertise.fizzo will choose not to advertise and pop hop will choose to advertise.both firms will choose not to advertise.again, suppose that both firms start off not advertising. if the firms decide to collude, what strategies will they end up choosing? fizzo will choose not to advertise and pop hop will choose to advertise.both firms will choose not to advertise.fizzo will choose to advertise and pop hop will choose not to advertise.both firms will choose to advertise.