The cost of a leading liquid laundry detergent in different sizes is given below.
a. Using "size" as the independent variable and "cost" as the dependent variable, make 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: y = 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. Use the two points in (e) and (f) to plot the least squares line on your graph from (a).
h. Does it appear that a line is the best way to fit the data? Why or why not?
i. Are there any outliers in the above data?
j. Is the least squares line valid for predicting what a 300 ounce size of the laundry detergent would cost? Why or why not?
k. What is the slope of the least squares (best-fit) line? Interpret the slope.