5E

1- Decide whether the following statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain your reasoning.

I had originally suspected that an increase in variable E would cause a decrease in variable F, but I no longer believe this because I found no correlation between the two variables.

The statement

does not make sense.

makes sense.

Originally,

a negative

a positive

no

correlation was suspected. Since no correlation was found, there is apparently

no

a negative

a positive

relationship between the variables.

2- For the following pair of variables, state the units that might be used to measure each variable. Then state whether you believe that the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. Explain your reasoning.

The age of a person and time spent on social networking sites

To measure age, the unit

minutes per website

degrees Fahrenheit

hours

years since birth

might be used.

3- For the following pair of variables, state the units that might be used to measure each variable. Then state whether you believe that the two variables are correlated. If you believe they are correlated, state whether the correlation is positive or negative. Explain your reasoning.

Fertility rate of women and life expectancy in a country

To measure fertility rate of women, the unit

pounds

degrees of latitude

years

children per woman

might be used.

4- Consider the following statement about a correlation. State the correlation clearly (for example, there is a positive correlation between variable A and variable B). Then state whether the correlation is most likely due to coincidence, a common underlying cause, or a direct cause. Explain your answer.

Automobile gas mileage decreases with tire pressure.

There is

a positive

no

a negative

correlation between gas mileage and tire pressure.