Question

Use the following information to answer Question 3 to Question 7 :

The closing stock price of Amazon.com, Inc. for the past 9 days is shown: 86, 88, 87, 86, 85, 90, 93, 82, 89

3. (16 points) The standard deviation of the sample is

4. (12 points) The median of the sample is

5. (24 points) IQR of the sample is

6. (10 points) Mode of the sample is

7. (10 points) Range of the sample is

Answer 1

( 3 )

standard deviation :

For the given data mean = 87.3333

Create the following table.

data	data-mean	(data - mean)2
86	-1.3333	1.77768889
88	0.66670000000001	0.44448889000001
87	-0.33329999999999	0.11108889
86	-1.3333	1.77768889
85	-2.3333	5.44428889
90	2.6667	7.11128889
93	5.6667	32.11148889
82	-5.3333	28.44408889
89	1.6667	2.77788889

Standard deviation = 3.1623

( 4 )

( 5 )

The interquartile range is the difference between the third and first quartiles.

The third quartile is 89.5.

The first quartile is 85.5.

The interquartile range = 89.5 - 85.5 = 4.

The interquartile range of the data set is 4.

( 6 )

( 7 )

The lowest value is 82.

The highest value is 93.

The range = 93 - 82 = 11.

The range of data set is 11.