## Statistics homework help

**STAT 33001 Biostatistics**

**Project – Outline**

** **

You are expected to complete a mini project related to descriptive and/or inferential statistics.

The project must contain the following components

- Title of the project
- Introduction and Objectives
- Data collection: Data should be a real a data set (you may find the data on the internet, in published papers, but please provide the source).
- Display the data graphically using
- Compute all relevant summary statistics. You may here use R or other software for the calculations.
- Perform the inferential statistics (Interval estimation/ hypothesis testing etc.) Include the test statistics that you are using. You may here use R or other software for the calculations. Statistics homework help.
- Conclusions
- References

- The project should be typed using a
- Use complete
- The length of the project should be maximum
**4** - Work alone or in a group of up to
**5 people. Please submit only one project for each group. Include the name of all group members on the project.**

** **Study of Fuel Efficiency for Imported and Domestic Passenger Cars

When people go to shop for a new car one of the main criteria they look at is the fuel

efficiency of the car. Many people who use fuel efficiency to determine what car to purchase

lean toward foreign made cars claiming that they get more miles per gallon than American

made cars. This study attempts to use the data for the average miles per gallon for domestic

and imported vehicles over a 24 year period from 1990-2013 to determine whether fuel

efficiency should play a significant role in whether to purchase a foreign made car over an

American made car. Statistics homework help.

The following table lists the average fuel efficiency of domestic and imported vehicles

from 1990-2013 based on data from the U.S. Department of Transportation found at

www.rita.gov

Table 1

Fuel Efficiency for Passenger Cars (mpg)

Year Domestic Imported

1990 26.9 29.9

1991 27.3 30.1

1992 27.0 29.2

1993 27.8 29.6

1994 27.5 29.7

1995 27.7 30.3

1996 28.1 29.6

1997 27.8 30.1

1998 28.6 29.2

1999 28.0 29.0

2000 28.7 28.3

2001 28.7 29.0

2002 29.1 28.8

2003 29.1 29.9

2004 29.9 28.7

2005 30.5 29.9

2006 30.3 29.7

2007 30.6 32.2

2008 31.2 31.8

2009 32.1 33.8

2010 33.1 35.2

2011 32.7 33.7

2012 34.4 36.4

2013 35.5 37.1

28 30 32 34 36

Boxplot for Imported MPG

28 30 32 34

Boxplot for Domestic MPG

Five Number Summary for the fuel efficiency of a Domestic passenger car with the

corresponding boxplot

Table 2

Five Number Summary for the fuel efficiency of an

Imported passenger car with the corresponding

boxplot

Table 3

Line graph comparing the fuel efficiency of a domestic vehicle to an imported vehicle from

1990-2013

Domestic mpg

Minimum 26.90

1

st Quartile 27.80

Median 28.90

3

rd Quartile 30.75

Max 35.50

Mean 29.69

Imported mpg

Minimum 28.30

1

st Quartile 29.20

Median 29.90

3

rd Quartile 31.90

Max 37.10

Mean 30.88

Bar graph comparing the fuel efficiency of a domestic vehicle to an imported vehicle from 1990-

2013

Domestic Imported

2 8 3 0 3 2 3 4 3 6

Side-by-side box plot

>

Determine whether the fuel efficiency varies enough that it should play a role in whether to

purchase an American or foreign made car. Statistics homework help.

H0

: μimported=μdomestic

Ha

: μimported ≠ μdomestic

Using the two sample t-test we get the following test statistic

t

0=

x1−x2

√

s1

2

n1

+

s2

2

n2

=1.678

and critical value t

0.025=¿2.069.

A 95 percent confidence interval is given by

(-0.2377, 2.62104).

Since the test statistic is smaller than the critical value we fail to reject the null hypothesis.

Therefore fuel efficiency should not play a significant role in whether to purchase a foreign or

an American made vehicle.

References

United States, Bureau of Transportation Statistics, Department of Transportation. “Table 4-23:

Fuel Efficiency of U.S. Light Duty Vehicles”. Retrieved August 4, 2015, from:

http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/

national_transportation_statistics/html/table_04_23.html. Statistics homework help.