Transcript text: Identify the level of measurement of the data, and explain what is wrong with the given calculation.
In a set of data, course grades are represented as 100 for ' $A$ ', 200 for ' $B$ ', and 300 for ' $C$ '. The average (mean) of the 689 course grades is 231.2.
The data are at the $\square$ level of measurement.
What is wrong with the given calculation?
A. Such data should not be used for calculations such as an average (mean).
B. The true average (mean) is 195.4.
C. One must use a different method to compute the average (mean) of such data.
D. There is nothing wrong with the given calculation.