Data are collected about the amount of time, in minutes, each band member spends practicing. how does a single outlier change the lower and upper quartiles of the collected data? a. a single outlier causes the values of the quartiles to move slightly toward each other. b. a single outlier causes the values of the quartiles to move slightly away from the outlier. c. a single outlier doubles the values of the quartiles. d. a single outlier does not affect the values of the quartiles.