Chapter 7, Problem 3E

(a)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same.

Answer to Problem 3E

Altitude would be the explanatory variable and the temperature would be the response variable.

There is a negative correlation, linear relationship. The relationship is moderately strong.

Explanation of Solution

Now, we have to find out for the: When climbing mountains; altitude and temperature.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that, altitude is the explanatory variable and temperature is the response variable because altitude predicts the temperature over the mountains when climbing.

The relationship is negative because as altitude increases then the temperature tends to decrease. The relationship is linear because as altitude increases, the temperature is expected to decrease by the same amount each time. The relationship is strong because the relationship between the two is almost entirely linear.

(b)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same

Answer to Problem 3E

Ice cream would be the explanatory variable and air conditioner would be the response variable.

There is a positive, linear relationship. The relationship is moderatelystrong.

Explanation of Solution

Now, we have to find out for the: For each week; ice cream cones sales and air conditioner sales.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that,ice cream cone sales is the explanatory variable and air conditioner sales is the response variable because it does not matter which variable is the explanatory or response variable as they do not affect each other.

The relationship is positive because as ice cream sales increases, the air conditioner sales also increase as they both are used by people in summers. The relationship is linear because as ice cream increases by one unit, air conditioner also increases by the same amount each time as they do not affect each other. The relationship is moderately strong because the relationship between the two is likely almost completely linear.

(c)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same

Answer to Problem 3E

Age is the explanatory variable and Grip strength is the response variable.

Curve would be expected to be curved down. The relationship is moderately strong.

Explanation of Solution

Now, we have to find out for the: People; age and grip strength.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that,age is the explanatory variable and grip strength is the response variable because grip strength is based on age.

The curve would be expected to be curved down because babies and elders do not have as much strength as adults and the relationship is moderately strong because the relationship between the two is likely almost completely linear.

(d)

To determine

To find out which variable you want to use as the explanatory and response variable and why and what would you expect to see in the scatterplot and also discuss the likely direction, form and strength for the same

Answer to Problem 3E

Blood alcohol levelis the explanatory variable and the reaction time is the response variable.

The relationship isa negative correlation, linear, and moderately strong.

Explanation of Solution

Now, we have to find out for the: Drivers; blood alcohol level and reaction time.

We know that, the response variable is the focus of a question in a study or experiment. An explanatory variable is one that explains changes in that variable. It can be anything that might affect the response variable.

As we can see that,blood alcohol level is the explanatory variable and the reaction time is the response variable because reaction time depends on the blood alcohol level and not the other way around.

The relationship is negative because as blood alcohol level increases, the reaction timetends to decrease. The relationship is linear because as blood alcohol levelincreases by one unit, reaction time decreases by the same amount each time. The relationship is moderately strong because the relationship between the two is likely almost completely linear.