Find an equation of the tangent line to the graph of the function f(x) = esec(x) at the point (*, ev2). 4

A marketing firm wishes to test the effectiveness of the audio/visual presentation of certain information as opposed to the purely audio presentation of the information.  To this end 100 volunteers were given a 10 minute presentation in which the information was presented in an audio/visual format.  A second group of 100 volunteers was presented the same information in a purely audio format.  Each person in each of the two groups was asked the same 20 questions related to the information in the presentation.   The audio/visual group had an average of 10.5 correct responses with a sample standard deviation of 4.  The purely audio group had an average of 9.4 correct responses with a standard deviation of 3.  The marketing firm believes this means that the audio/visual format leads to better retention of the information. We test the hypotheses H0:  1 -2=0 versus Ha: 1 -2>0 at a 2% level of significance.   Here  denotes  1 the population average number of correct responses for…

In 2004 it surfaced in Reader's Digest presented as having happened to a teacher at an unnamed community college. Four students walked in halfway through American history test my father was giving at the local community college. "Sorry," they said, "we had a flat tire." An understanding man, Dad said that if they could answer just one question correctly, he would give them each an "A" for the exam. The students agreed. So my father handed each one a piece of paper, placed them in four separate comers and said, "Write down which tire was flat." Kurt Smith What is the probability that these four students would give identical answers if they hadn't had a flat tire? Why?

When does Counterbalancing will be inappropriate?