Eric Kannengieszer and Colin Buckley. Our objective was to run a series of tests involving gas...
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GAS PRICES Eric Kannengieszer and Colin Buckley vs.
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Transcript of Eric Kannengieszer and Colin Buckley. Our objective was to run a series of tests involving gas...
GAS PRICESEric Kannengieszer and Colin Buckley
vs.
BACKGROUND
Our objective was to run a series of tests involving gas prices Exxon vs. Lukoil Pennsylvania vs. New Jersey Exxon PA vs. Exxon NJ Lukoil PA vs. Lukoil NJ
Wanted to determine what station was cheapest
WHAT WE DID
We Google Maps searched PA and NJ Exxon and Lukoil stations and randomly selected 10 of each. We numbered each location and used our
calculator to randomly select the stations We picked four days from our break
and called each location to record the prices
EXXON VS. LUKOIL
Ho: µE=µL Ha: µE≠µL Conditions:
1. 2 Independent SRS 1. yes, performed 2 SRS2. pop1≥10n 2. more than 800 Lukoil’s/Exxon’s pop2≥10n3. 2 normal populations 3. histograms shows normal populations
Conditions met →Use students t distribution →2 sample t-test
EXXON VS. LUKOIL
We reject the Ho because the p-value is smaller than alpha.05.
We have sufficient that the average price of Exxon gas is not equal to the average price of Lukoil gas.
Station
0
4
8
12
16
E
4
8
12
16
L
2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
Price
Collection 2 Histogram
734.2
80120543.
80020191.
)111.318288.3( 2
t 0071.967.128|734.22 dftP
NEW JERSEY VS. PENNSYLVANIA
Ho: µNJ=µPA Ha: µNJ<µPA Conditions:
1. 2 Independent SRS 1. yes, performed 2 SRS2. pop1≥10n 2. more than 800 Lukoil’s/Exxon’s pop2≥10n3. 2 normal populations 3. histograms shows normal populations
Conditions met →Use students t distribution →2 sample t-test
VS.
NEW JERSEY VS. PENNSYLVANIA
We reject the Ho because the p-value is smaller than alpha .05.
We have sufficient that the mean price of New Jersey is less than the mean price of Pennsylvania.
NJ
PA
2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
Price
Collection 2 Box Plot
94.12
80138589.
800943444.
)26825.302563.3( 2
t 0001.275.139|94.12 dftP
EXXON NJ VS. EXXON PA
Ho: µNJ=µPA Ha: µNJ<µPA Conditions:
1. 2 Independent SRS 1. yes, performed 2 SRS2. pop1≥10n 2. more than 400 Exxon’s pop2≥10n3. 2 normal populations 3. histograms shows normal populations
Conditions met →Use students t distribution →2 sample t-test
EXXON NJ VS. EXXON PA
We reject the Ho because the p-value is smaller than alpha .05.
We have sufficient evidence that the mean price of Exxon’s in NJ is less than that of Exxon’s in PA.
NJ
PA
2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
Exxon
Collection 4 Box Plot
55.11
40151767.
400862777.
)34225.30235.3( 2
t 0001.824.61|55.11 dftP
LUKOIL NJ VS. LUKOIL PA
Ho: µNJ=µPA Ha: µNJ<µPA Conditions:
1. 2 Independent SRS 1. yes, performed 2 SRS2. pop1≥10n 2. more than 400 Lukoil’s pop2≥10n3. 2 normal populations 3. histograms shows normal populations
Conditions met →Use students t distribution →2 sample t-test
LUKOIL NJ VS. LUKOIL PA
We reject the Ho because the p-value is smaller than alpha .05.
We have sufficient evidence that the mean price of Lukoil’s in NJ is less than that of Lukoil’s in PA.
NJ
PA
2.8 2.9 3.0 3.1 3.2 3.3
Lukoil
Collection 5 Box Plot
536.8
400681208.
40102844.
)19425.302775.3( 2
z
0001.6975.67|536.8 dftP
BIAS AND ERROR
Miscommunication over the phone
Individual stores within the chain have the same price
CONCLUSIONS
New Jersey gas is substantially cheaper than Pennsylvania gas
Exxon has a wider range of price, but Lukoil has a lower mean price overall
NJ Lukoil’s is the cheapest
If you want gas, go to New Jersey and find a Lukoil
