Upright vacuum cleaners have either a hard body type or a soft body type. Shown are the weights in pounds of a random sample of each type. A reviewer wishes to see if the mean weights of the two types are different. Hard body types

20	17	18	19	16	17	15	21	24
15	18	18	12	14	17	17	18

Soft body types

23

12

12

12

12

14

Find the 95% confidence interval for the difference of the means.