Question

1.) Calculate both the sample and the population standard deviations using the data below.

x	14	20	26	18	6	24

Please show the following answers to 1 decimal place.

Sample Standard Deviation (ss) =
Population Standard Deviation (σσ) =

Notice the different!

2.) The highway mileage (mpg) for a sample of 9 different models of a car company can be found below.

20

27

35

49

35

43

22

28

40

Find the mode:

Find the midrange:

Find the range:

Estimate the standard deviation using the range rule of thumb:

Now use technology, find the standard deviation:  (Please round your answer to 2 decimal places.)

3.) For a 4-unit class like Statistics, students should spend average of 12 hours studying for the class. A survey was done on 24 students, and the distribution of total study hours per week is bell-shaped with a mean of 12 hours and a standard deviation of 2.9 hours.

Use the Empirical Rule to answer the following questions.

a) 68% of the students spend between  hours and  hours on Statistics each week.

b) 95% of the students spend between  hours and  hours on Statistics each week.

c) 99.7% of the students spend between  hours and  hours on Statistics each week.

Answer 1