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The most commonly accepted tradition is that college students will study 2 hours outside of class for every hour in class. This means 30 hours/week for a full-time student taking 15 units (hours of class). An educator suspects that this figure is different now than in the past.

Claim 1: The average time full-time college students study outside of class per week is 30 hours.
Claim 2: The average time full-time college students study outside of class per week is not 30 hours.

To substantiate her claim, the educator randomly selects 1,500 college students and finds that they study an average of 27 hours per week with a standard deviation of 1.7 hours.

In order to assess the evidence, we need to determine:

how likely it is to observe a mean number of hours of studying outside of class per week that is different from 30 hours per week.
how likely it is in a random sample of 1,500 students to observe that the average number of hours spent per week studying outside of class is at most 27 hours, or at least 33 hours.
how likely it is in a random sample of 1,500 students to observe that the mean amount of hours of studying outside of class per week is 27 hours or less.
how likely it is in a random sample of 1,500 students to observe students studying an average of at most 27 or at least 33 hours per week outside of class, if the mean number is actually 30 hours per week.
how likely it is that the mean number of hours per week spent by students studying outside of class is 30.

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