The file ‘SUV' contains the overall miles per gallon (mpg) of 2010 family SUVs.
a) Compute the mean, median, and the mode.
b) Compute the variance, standard deviation, range, coefficient of variation, and Z scores.
c) Are the data skewed? If so, how?
2) The file ‘HotelUK' contains the room service price (in $) paid by US travelers in six British cities in 2009.
a) Compute the first quartile, the third quartile, and the interquartile range.
b) Construct a boxplot and describe its shape.
3) The file ‘Energy' contains the per capita energy consumption (in kilowatt-hours), for each of the 50 states and the District of Columbia during a recent year.
a) Compute the mean, variance, and standard deviation for the population.
b) What proportion of these states has per capita energy consumption within + or - 1 standard deviation of the mean, within + or - 2 standard deviations of the mean, and within + or - 3 standard deviations of the mean?
c) Compare your findings with what would be expected based on the empirical rule.
d) Repeat a) through c) with the District of Columbia removed. Have the results changed?
4) The file ‘Cereals' lists the calories and sugar (disregard carbohydrates) in grams, in one serving of seven breakfast cereals.
a) Compute the covariance.
b) Compute the coefficient of correlation.
c) Which do you think is more valuable in expressing the relationship between calories and sugar - the covariance of the coefficient of correlation? Explain.
d) Based on a) and b), what conclusions can you reach about the relationship between calories and sugar?