What is the standard deviation of the following data set rounded to the nearest tenth?

30, 26, 28, 32, 28, 30

3.7

2.0

3.6

1.9

Me its important ! marge runs an ice cream parlor. her speciality is triple chocolate sundaes. she can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . if she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?