1) Calculate the sample standard deviation of the data shown. Round to two decimal places.

x

24

28

15

11

12

21

29

17

sample standard deviation =

2)Suppose a set of data has mean =21 and standard deviation=1.6.

(Give answers accurate to three decimal places.)

1. What is the z-score for the data value =17? =
2. What is the z-score for the data value =22? =
3. What data value corresponds to the z=score: =1.2? =
4. What data value corresponds to the z=score: =-1.7? =

3)The maintenance department at the main campus of a large state university receives daily requests to replace fluorecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 42 and a standard deviation of 10. Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 22 and 42? Do not enter the percent symbol. ans = %

4)The mean score on a driving exam for a group ofdriver's education students is 72 points, with a standard deviation of 3points.ApplyChebyshev's Theorem.At least 75% of the exam scores fall between and. (Enter the smaller number first.)At least 88.9% of the exam scores fall between and. (Enter the smaller number first.)