Chapter PII, Problem 23RE

(a)

To determine

To explain why can’t use the linear model you created in exercise $\text{22}$ to see when smoking during pregnancy will cease altogether.

Explanation of Solution

It is given in the question that the organization Kids Count monitors issues related to children and the table is also given which shows a $50$ -state average of the percent of expectant mothers who smoked cigarettes during their pregnancies. Thus, the downward trend is showing positive result but we cannot use the linear model you created in exercise $\text{22}$ to see when smoking during pregnancy will cease altogether because the model is for predicting the smoking percentage not the year.

(b)

To determine

To create a model that could estimate the year in which the level of smoking would be $\text{0\%}$ .

Answer to Problem 23RE

   .

Explanation of Solution

It is given in the question that the organization Kids Count monitors issues related to children and the table is also given which shows a $50$ -state average of the percent of expectant mothers who smoked cigarettes during their pregnancies. Thus, the model that could estimate the year in which the level of smoking would be $\text{0\%}$ can be created as:

Thus, for constructing a linear model we will use Excel as we will first select the data in Excel and then go to the insert tab from where we will select the scatterplot option in the charts and when the scatterplot is constructed we will go to the design tab under the chart tools, from where we will select the quick layout option and select the layout with the equation option then the linear model is constructed in the scatterplot as:

  

Thus, the model is as:

  

(c)

To determine

To comment on the reliability of such a prediction.

Explanation of Solution

It is given in the question that the organization Kids Count monitors issues related to children and the table is also given which shows a $50$ -state average of the percent of expectant mothers who smoked cigarettes during their pregnancies. The linear model is:

  

Thus, we can say about the reliability of such a prediction that despite the strong correlation extrapolating to that value is not a very good idea.