Problem

College students at a large state university completed a survey about their academic and personal life. Questions ranged from "How many credits are you registered for this semester?" to "Would you define yourself as a vegetarian?" Four sections of an introductory statistics course were chosen at random from all the sections of introductory statistics courses offered at the university in the semester when the survey was conducted, and the 312 students who completed the survey were students registered in one of the four chosen sections.

In this exercise, we will use a subset of variables from the survey and use the collected data to answer three questions. Note that (1) these are real data, and (2) the symbol * in the worksheet means that this observation is not available (this is known as a "missing value").

Click theQuestionstab to see the questions about this problem that we will try to answer, and theVariablestab to see the variables in our dataset.

Variables

Math:Math SAT score

Verbal:Verbal SAT score

Credits:Number of credits the student is registered for

Year:Year in college (1=Freshman, 2=Sophomore, 3=Junior, 4=Senior)

Exer:Time (in minutes) spent exercising in a typical day

Sleep:Time (in hours) spent sleeping in a typical day

Veg:Are you a vegetarian (yes, no, some)

Cell:Do you own a cell phone (yes, no)

Questions

Q1. The mean verbal SAT score of all the students in this university is 580. Is this also the case for all stat students at this university? Note that verbal SAT scores in the U.S. have a standard deviation of 111.

Q2. Based on a recent study, roughly 80% of college students in the U.S. own a cell phone. Do the data provide evidence that the proportion of students who own cell phones in this university is lower than the national figure?

Q3. Adults in the U.S. average 7 hours of sleep a night. Is this also the mean for all stat students at this university?

What I am trying to figure out is this,

What value would the parameter of interest equal under the hypothesis of no change/no effect/no difference from the status quo?