When the background music was slow, the mean amount of bar purchases for a sample of 17 restaurant patrons was $30.47 with a standard deviation of $15.10. When the background music was fast, the mean amount of bar purchases for a sample of 14 patrons in the same restaurant was $21.62 with a standard deviation of $9.50. (a) assuming unequal variances, at ?=0.01, is the true mean higher when the music is slow?