Success in Calculus is Correlated with Being Competent

Of the 250 students in the Calculus Circus, 160 of them purchased and registered their clickers; 140 students brought their clickers to lecture today. (This is not bad, considering that today was the second time that class met.)

Of the 140 clicker-having students, nearly all of them were able to correctly answer all the questions about limits that were asked during class today.

Note that 140/250 = .56 and 160/250 = .64, so between 56% and 64% of students were able to follow directions about the clickers, at least to some extent. Is it a coincidence that the pass rate for this class is traditionally around 60%?

ps. Sorry about no post yesterday and not much until late today. My coauthor left today for some international travel, and I needed to finish off a chapter so that he could revise and edit it on the plane. Looks like everything is on track for meeting the deadline that's coming up in two weeks: Half the book needs to be done by September 10.