Outliers · Exercise 15

The cost of a leading liquid laundry detergent in different sizes is given in.
\begin{array}{|c|c|c|}\hline \text{Size (ounces)} & \text{Cost ($)} & \text{Cost per ounce} \\ \hline \text{16} & \text{3.99} & \\ \hline \text{32} & \text{4.99} & \\ \hline \text{64} & \text{5.99} & \\ \hline \text{200} & \text{10.99} & \\ \hline\end{array}

(a) Using “size” as the independent variable and “cost” as the dependent variable, draw a scatter plot.
(b) Does it appear from inspection that there is a relationship between the variables? Why or why not?
(c) Calculate the least-squares line. Put the equation in the form of: ŷ = a + bx
(d) Find the correlation coefficient. Is it significant?
(e) If the laundry detergent were sold in a 40-ounce size, find the estimated cost.
(f) If the laundry detergent were sold in a 90-ounce size, find the estimated cost.
(g) Does it appear that a line is the best way to fit the data? Why or why not?
(h) Are there any outliers in the given data?
(i) Is the least-squares line valid for predicting what a 300-ounce size of the laundry detergent would you cost? Why or why not?
(j) What is the slope of the least-squares (best-fit) line? Interpret the slope.

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Introductory Statistics 2e · §12.6 Outliers · Exercise 15