# calculation of the mean

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## calculation of the mean

It is well known that smaller classes are generally more effective. According to the National Center for Education Statistics, California has a mean of 20.9 students per teacher, and Alaska has a mean of 16.8 students per teacher. If we combine the two states, we might find the mean number of students per teacher to be 18.85, as in the calculation shown below, but is this result correct? Why or why not?