For each of the following questions suppose you want to coll

For each of the following questions, suppose you want to collect data and make a scatterplot to help answer the question. (i) Which variable would you use as the explanatory variable and which would you use as a response variable? Why? (ii) What would you expect to see in the scatterplot? Discuss the likely direction (positive, negative, or either), form (linear, nonlinear, no pattern), and strength. A) Do people who spend more on haircuts tend to own more pairs of shoes? B) Do magazines with more pages also use more ink? C) Do students who live far from school tend to get less sleep? D) Do students who miss class less often get better test scores? E) Do professional baseball teams with younger players tend to hit more home runs?

Solution

i)

a)

explanatory variable   people who spend more on haircuts

response variable more pairs shoes

b)

explanatory variable   magazine with more pages

response variable     magazine with more ink

c)

explanatory variable    students who live far from school

response variable    get less sleep

d)

explanatory variable   students who miss class less often

response variable    get better test score

e)

explanatory variable   teams with younger players

response variable     hit more home runs

ii)

a)

I would expect to see no pattern at all because hair cut and shoes they are not have relation at all

if you spend more in haircuts maybe you would not have money for more shoes, you can maybe use your money only in haircuts

b)

I would expect to see a linear form with positive direction because the pagazine that have more pages

will use more ink, with the ink you create the page so there is a relationship here,

c)

I would expect to see a linear form with negative direction because the students who live far from school need to get early to arrive early at school, that means sleep less than other students that maybe live more closer from school

If you live more far from school you will sleep less so for that reason will be negative

more distance = less hours for sleeping

d)

I would expect to see a linear form with negative direcction because there is a relation between those variables

if you miss class less often then you will understand the topic and you would be able to answer all your homeworks because you understand the class, or if you didnt understand you would be able to speak with your teacher and he will explain again.

Conclusion: less miss class often = better scores in your tests

e)

I would expect to see a linear form with positive direction because for those variables there is a relationship

if you have more younger players they would have more energy and strenght

Conclusion

more younger players = more home runs

positive directions