Refer to the data on the school buses in the Buena School District. Set up a variable that divides the age of the buses into three groups: new (less than 5 years old), medium (5 but less than 10 years), and old (10 or more years). The median maintenance cost is $456. Based on this value, create a variable for those less than or equal to the median (low maintenance) and those more than the median (high maintenance). Finally, develop a table to show the relationship between maintenance cost and age of the bus.
a. What percentage of the buses are new?
b. What percentage of the new buses have low maintenance?
c. What percentage of the old buses have high maintenance?
d. Does maintenance cost seem to be related to the age of the bus? Hint: Compare the maintenance cost of the old buses with the cost of the new buses? Would you conclude maintenance cost is independent of the age?
Question: The data set shown below gives the calories and salt content in 17 brands of meat hot dogs.
a) Enter the data set into excel. Using excel perform a least squares regression on the data set. Use Sodium as the y variable and Calories as the x variable. Make a scatter plot with the regression line plotted as well. Using excel compute the correlation coefficient.
b) Insert the plot your created into a word document. Discuss the scatter plot and regression line. Are their outliers? Does your correlation coefficient support your analysis? Does it tell you anything else?
c) If there is an outlier remove the outlier from the data set and repeat the previous two parts.
d) Can you conclude that hot dogs with more calories will have more sodium (i.e. discuss correlation and causation)?