stineFoster4-54

CAR MODELS SOLD IN US 2003-2004 STINE & FOSTER 4 - 53

CARS PROBLEM Another columns in this data file cars gives the rating highway gasoline mileage and city gasoline mileage (in miles per gallon) for 233 car sold in the United States during 2003 and 2004.

SUMMARY STATISTICS All Observations City Highway

Mean Median Var StDev CV IQR Skewness 19.24 19 90.93 9.54 0.5 5 -7.65 25.68 26 102.43 10.12 0.39 7 -7.7

Exclude Missing Observation City Highway

Mean Median Var StDev CV IQR Skewness 19.75 19 30.53 5.53 0.28 5 2.74 26.22 26 35.30 5.94 0.23 7 1.57

A)

PRODUCE A HISTOGRAM OF THESE DATA. DESCRIBE AND INTERPRET THE HISTOGRAM.

B)

COMPARE THE HISTOGRAM TO THE BOX PLOT. WHAT DOES THE HISTOGRAM TELL YOU THAT THE BOX PLOT DOES NOT, AND VICE VERSA?

MPG CITY

MPG HIGHWAY

C)

FIND THE MEAN AND STANDARD DEVIATION OF THE RATED MILEAGES. HOW ARE THESE RELATED TO THE HISTOGRAM, IF AT ALL?

All Observations City Highway

Mean Median Var StDev CV IQR Skewness 19.24 19 90.93 9.54 0.5 5 -7.65 25.68 26 102.43 10.12 0.39 7 -7.7

Exclude Missing Observation City Highway

Mean Median Var StDev CV IQR Skewness 19.75 19 30.53 5.53 0.28 5 2.74 26.22 26 35.30 5.94 0.23 7 1.57

D)

FIND THE COEFFICIENT OF VARIATION AND BRIEFLY INTERPRET ITS VALUE.

All Observations City Highway

Mean Median Var StDev CV IQR Skewness 19.24 19 90.93 9.54 0.5 5 -7.65 25.68 26 102.43 10.12 0.39 7 -7.7

Exclude Missing Observation City Highway

Mean Median Var StDev CV IQR Skewness 19.75 19 30.53 5.53 0.28 5 2.74 26.22 26 35.30 5.94 0.23 7 1.57

E)

IDENTIFY ANY UNUSUAL VALUES (OUTLIERS). DO YOU THINK THAT THESE ARE CODING ERRORS?

A)

PRODUCE A HISTOGRAM OF THESE DATA. DESCRIBE AND INTERPRET THE HISTOGRAM.

B)

COMPARE THE HISTOGRAM TO THE BOX PLOT. WHAT DOES THE HISTOGRAM TELL YOU THAT THE BOX PLOT DOES NOT, AND VICE VERSA?

MPG CITY

MPG HIGHWAY

F)

HOW DOES A CAR THAT GETS 20 MILES PER GALLON STACK UP AGAINST THESE MODELS? IS IT TYPICAL OR DOES IT GET RELATIVELY LOW MILE OR HIGH MILEAGE?