The table below shows the index of exposure and the cancer mortality rate (deaths per 100,000) for the nine counties affected. Higher index values represent higher levels of contamination
|County||Index of exposure (x)||Cancer mortality per 100,000 (y)|
a) Plot y vs x and comment on whether the relationship is approximately linear.
b) Find the equation of the least squares line.
c)What does the slope of the line tell you about the relationship between index of exposure and mortality rate?
d)What is the predicted mortality rate for a county with a value of 4 for index of exposure?
e)What is the predicted mortality rate for a county with a value of 15 for index of exposure? Are there any problems with using the regression equation to make this prediction? (Look at the Minitab output )
f) Calculate the residual for each of the data points.
g) What proportion of the variability in y is explained by x?
h)Calculate the correlation between index of exposure and mortality rate.
|STATISTICS 2080 HOMEPAGE||MINITAB TUTORIAL HOMEPAGE|