Turn in Lab 2 and these problems:

(You might want to read the Hints at the bottom of this screen before trying these problems on the computer.)

1.  Consider the personal data collected in class.  We're going to focus on three variables: commute time, hours of TV watched, and weight.  For each of these variables, do the following:
    a) Classify as quantitative/qualitative, continuous/discrete.
    b) Without looking at any graphics, describe the shape you would expect for the distribution of this variable:  symmetric, skewed?  Explain why.
    c) What's a typical value for this variable for students in 110A and B?
    d) Make a histogram or stem and leaf plot of these variables. Describe the distribution.  Are there outliers? Gaps? What is the shape?

2.  People with short commutes have more time to watch TV.  Do you see any evidence that the length of the commute is related to the amount of TV watched?  What is this evidence?  Can you give an explanation for your conclusion?

3. Are weight and the amount of TV watched related?  This is an ambitious question, so lets make it simpler: is there evidence that the hours of TV watched and weight are related in  our data set?  Use any means you like to answer this question, but be sure to support your answer with the necessary graphs or numbers.
(Hint: there may or may not be two outliers in the TV variable.  If these were removed, would your conclusions change?)

4. Suppose we randomly select one of the people whose answers appear in the class data set.  Find the probability that this person
    a) weighs less than 120 pounds
    b) watched more than 2 hours of TV last night
    c) weighs less than 120 pounds  AND watched more than 2 hours of TV last night?
    d) weighs less than 120 pounds OR watched more than 2hours of TV last night?
    e) weighs more than 120 pounds AND watched more than 2 hours of TV last night?
Hint; A Venn diagram might be helpful for this and the next problem.

5. Again, a person is randomly selected from the class data set, only this time the person is chosen from those who watched more than 2 hours of TV last night.     a) Find the probability that this person weighs less than 120 pounds, given that they watched more than 2 hours of TV last night.
b) Find the probability that this person weighs 120 pounds or more, given that they watched more than 2 hours of TV last night.
c) Find the probability that this person weigs less than 120 pounds given that they watched 2 hours or LESS of TV last night.

6. Let X represent the number of heads in 3 tosses of a coin.
a) Write a table giving the values and probabilities of X.
b) Make a graphic of this distribution.
c) What is the probability of getting 2 or more heads?
d) What is the probability of getting at least 1 head?
 

ARC HINTS.  You might find it helpful to learn some new ARC techniques.