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.)

5) Cholesterol levels (mg/dL) were collected from a random sample of patients two days after they had a heart attack.

Click on the Data button shown below to display the data. Data

(a) Find the range. Put the answer in the first box and the correct units in the second box. Range = (b) Find and interpret the (sample) standard deviation. Put the answer in the first box, rounded to 2 decimal places, and the correct units in the second box. Standard deviation = Interpret:

• The average spread of the cholesterol level of patients two days after they had a heart attack from the mean.
• The difference between the largest and the smallest cholesterol level of patients two days after they had a heart attack.
• The average spread of the cholesterol level of patients two days after they had a heart attack from the median.
• The average cholesterol level of patients two days after they had a heart attack.