Similarly, we might think that increasing the default tip suggestions made some riders angry and would make them respond by tipping zero dollars. Run a logistic regression in which the depenent variable is the zero$\_$tip and the independent variables are CMT$,$ post$\_$feb, and CMTxpost. At the mean, what was the marginal effect of increasing the default tip suggestions on the probability that a rider would decide to top zero dollars? Store your answer in the variable effect$\_$on$\_$zero$\_$tip as a float. Is the effect statistically significant? Store your answer in the variable stat$\_$sig as either the string "yes" or $"$no$".$

effect$\_$on$\_$zero$\_$tip $=$ None

stat$\_$sig $=$ None

# YOUR CODE HERE

raise NotImplementedError$()$