There are two scales that measure communication apprehension. The McCroskey scale has an average score of 60 with a standard deviation of 10. The Burgoon scale has an average score of 90 with a standard deviation of 8. A higher score of both scales indicates greater apprehension.
a) Marcia scores 50 on the McCroskey test and Teri scores 60 on the Burgoon test. Who is more communication apprehensive?
b) We further know that scores on the McCroskey scale are normally distributed. What is the probability that a randomly selected person scores less than 30?
c) Find the score on the McCroskey test that is the 97th percentile.