3.1 - 1
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
3.1 - 2
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
1
)( 2
n
xxs
3.1 - 3
1
)( 2
n
xxs
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Calculate the mean
3.1 - 4
Example 14: Auto Sales
1
)( 2
n
xxs
Find the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Calculate the mean
3.1 - 5
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
1
)( 2
n
xxs
3.1 - 6
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
1
)( 2
n
xxs
3.1 - 7
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
1
)( 2
n
xxs
3.1 - 8
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
11.2-12.612.612.612.612.612.612.6
1
)( 2
n
xxs
3.1 - 9
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4 1
)( 2
n
xxs
3.1 - 10
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7
1
)( 2
n
xxs
3.1 - 11
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.6
1
)( 2
n
xxs
3.1 - 12
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.2
1
)( 2
n
xxs
3.1 - 13
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.8
1
)( 2
n
xxs
3.1 - 14
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Create a column of each value minus the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1
)( 2
n
xxs
3.1 - 15
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Square each deviation from the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1
)( 2
n
xxs
3.1 - 16
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Square each deviation from the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.96 1
)( 2
n
xxs
3.1 - 17
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Square each deviation from the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.49
1
)( 2
n
xxs
3.1 - 18
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Square each deviation from the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.36
1
)( 2
n
xxs
3.1 - 19
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Square each deviation from the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.360.04
1
)( 2
n
xxs
3.1 - 20
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Square each deviation from the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.360.040.64
1
)( 2
n
xxs
3.1 - 21
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Square each deviation from the mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.360.040.642.89
1
)( 2
n
xxs
3.1 - 22
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Sum the squared deviations from the
mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.360.040.642.89
1
)( 2
n
xxs
3.1 - 23
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
Sum the squared deviations from the
mean
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.360.040.642.896.38
1
)( 2
n
xxs
3.1 - 24
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.360.040.642.896.38
5
38.6
1
)( 2
n
xxs
3.1 - 25
Example 14: Auto SalesFind the variance and standard deviation for the amount of European auto sales for a sample of 6 years. The data are in millions of dollars.
11.2, 11.9, 12.0, 12.8, 13.4, 14.3
x
11.211.912.012.813.414.3
12.612.612.612.612.612.6
-1.4-0.7-0.60.20.81.7
1.960.490.360.040.642.896.38 13.1
5
38.6
1
)( 2
n
xxs