A group of randomly selected wireless earbud users was asked, "How often do you replace your wireless ear buds?" The data (in months) are as follows:

28	30	20	24
34	25	32	26
31	21	38	30
27	35	18	28
29	32	30	22
16	22	20	21

a) Determine the mean, median, and mode for this sample. What does this suggest about the shape of the distribution, and why?

b) Calculate the variance and standard deviation, rounding to one decimal place.

c) Find the range.