1. Auto Accidents: What’s responsible?
Group 8
Janelle Chang
Helena Jeanty
Rhiana Quail

2. DISCLAIMER!!! Weather conditions Drivers’ mental health
Drivers’ physical health
Time of day
Time of year

3. Sorting the Data... National vs. Regional Reasoning… National:
all 50 states (not including DC)
Regional:
Region 1 ~ North East
Region 2 ~ South East
Region 3 ~ South MidWest
Region 4 ~ North MidWest
Region 5 ~ South West
Region 6 ~ North West
Reasoning…
Allows one to view any type of national behavior
Allows for comparisons to be made within the United States

4. Normalizing Data Reason:
Every entry needs to be expressed in a “standard” proportion so that the data can be evaluated equally.
State populations differs
Number of states per region differ
Basic assumption: more people = more cars = higher number of automobile fatalities.

5. Testing #1: Does alcohol affect the number of drivers killed in car accidents?
assumption
Alcohol affects the number of people killed in car accidents BUT is not the only contributing factor.
Younger people probably drink more irresponsibly so more likely to be involved and be responsible for fatal car accidents.
#2: Does a combination of age and alcohol affect the number of people (including drivers) killed in car accidents? #3: Do individual regions mimic national data?

6. t-Test H0: tot. drivers killed = drunk drivers killed
For each region:
H0: tot. drivers killed = drunk drivers killed
H1: tot. drivers killed  drunk drivers killed
t-Test:
 = 0.05, 95% confidence
2-sided test
df = (# obs) - 1

7. t-Test (#1) Rejecting H0 Reject H0: | t| > t15 ie. 6.36 > 2.131
Source | SS df MS Number of obs =
F( 1, 15) =
Model | e e Prob > F =
Residual | e e R-squared =
Adj R-squared =
Total | e e Root MSE = 1.7e-07
reg1normki~d | Coef Std. Err t P>|t| [95% Conf. Interval]
reg1normdr~k |
_cons | e e e e-07
Reject H0: | t| > t15
ie > 2.131

8. Regression: driverskilled = 1.37e-07+ 125.8276 * drunkdriverskilled

9. t-Test Accepting H0 Accept H0: | t| < t2
Source | SS df MS Number of obs =
F( 1, 2) =
Model | e e Prob > F =
Residual | e e R-squared =
Adj R-squared =
Total | e e Root MSE = 8.1e-08
reg5normki~d | Coef Std. Err t P>|t| [95% Conf. Interval]
reg5normdr~k |
_cons | e e e e-07
Accept H0: | t| < t2
ie < 3.18 < 4.303

10. Regression: driverskilled = 110.3849 + 1.27e-07 *drunkdriverskilled

11. Testing #1: Does alcohol affect the number of drivers killed in car accidents?
assumption
Alcohol affects the number of people killed in car accidents BUT is not the only contributing factor.
Younger people probably drink more irresponsibly so more likely to be involved and be responsible for fatal car accidents.
#2: Does a combination of age and alcohol affect the number of people (including drivers) killed in car accidents? #3: Do individual regions mimic national data?

12. F-Test For each region: H0: 1 = 2 = 0
H1: 1  2 (at least one  i  0)
F-Test:
 = 0.05, 95% confidence
1-sided test

13. F-Test (#2) Rejecting H0 Reject H0: F0.025, 2, 8 > 4.46
Source | SS df MS Number of obs =
F( 2, 8) =
Model | e e Prob > F =
Residual | e e R-squared =
Adj R-squared = T
Total | e e Root MSE = 2.1e-07
reg1normki~d | Coef Std. Err t P>|t| [95% Conf. Interval]
reg1normdr~k |
personskil~d |
_cons | e e e e-07
Reject H0: F0.025, 2, 8 > 4.46
ie > 4.46
peoplekilled = 2.69e * drunkdrivers
* agekilled

14. F-Test Accepting H0 Accept H0: F0.025, 2, 5 < 5.79
Source | SS df MS Number of obs = 8
F( 2, 5) = 3.64
Model | e e Prob > F =
Residual | e e R-squared =
Adj R-squared =
Total | e e Root MSE = 6.7e-08
reg3normki~d | Coef Std. Err t P>|t| [95% Conf. Interval]
reg3normdr~k |
agekilled |
_cons | e e e e-07
Accept H0: F0.025, 2, 5 < 5.79
ie < 5.79
driverskilled = 1.38e * drunkdrivers * agekilled

15. Testing #1: Does alcohol affect the number of drivers killed in car accidents?
assumption
Alcohol affects the number of people killed in car accidents BUT is not the only contributing factor.
Younger people probably drink more irresponsibly so more likely to be involved and be responsible for fatal car accidents.
#2: Does a combination of age and alcohol affect the number of people (including drivers) killed in car accidents? #3: Do individual regions mimic national data?

16. Confidence Intervals (#3)
Confidence Interval of the mean for the National Data
National Mean of drivers killed: E-07
Confidence Interval
( E-07, E-07)
( E E-08 , E E-08)

17. Region Results with Confidence Intervals
Lies within National CI
Region
Mean

18. Graph of National Data

19. ANOVA Test H0: national = reg 1 = reg 2 = .….. = reg 6
The number of divers killed in car accidents is independent of the region in which they occur.
Reject H0 if F > F0.95, 3, 2 = 19.2
F = < 19.2 so accept H0

20. Conclusions
Nationally, 4 out of the 6 regions rejected the F-test null hypothesis => there is a correlation between age, BAC, and the number of drivers killed.
Regionally, 4 out 6 supported the national data trend. The regressions carried out confirm that the number of people killed depends on the number of drunk drivers.
Regions do not reflect the national trend for the average number of drivers killed.
The number of drivers killed does not depend on the region in which they occur.