Here is the data we used for our research:
State
|
Year
|
Population
|
Fatal motor vehicle crashes
|
Motor vehicle crash deaths
|
Rate
|
NH
|
2005
|
1309940
|
156
|
166
|
12.7
|
NH
|
2006
|
1314895
|
116
|
127
|
9.7
|
NH
|
2007
|
1315828
|
122
|
129
|
9.8
|
NH
|
2008
|
1315809
|
128
|
139
|
10.6
|
NH
|
2009
|
1324575
|
97
|
110
|
8.3
|
NH
|
2010
|
1316470
|
120
|
128
|
9.7
|
NH
|
2011
|
1318194
|
84
|
90
|
6.8
|
NH
|
2012
|
1320718
|
101
|
108
|
8.2
|
NH
|
2013
|
1323459
|
124
|
135
|
10.2
|
NH
|
2014
|
1326813
|
89
|
95
|
7.2
|
MA
|
2005
|
6398743
|
418
|
442
|
6.9
|
MA
|
2006
|
6437193
|
404
|
430
|
6.7
|
MA
|
2007
|
6449755
|
390
|
417
|
6.5
|
MA
|
2008
|
6497967
|
337
|
363
|
5.6
|
MA
|
2009
|
6593587
|
308
|
334
|
5.1
|
MA
|
2010
|
6547629
|
299
|
314
|
4.8
|
MA
|
2011
|
6587536
|
321
|
337
|
5.1
|
MA
|
2012
|
6646144
|
333
|
349
|
5.3
|
MA
|
2013
|
6692824
|
309
|
326
|
4.9
|
MA
|
2014
|
6745408
|
310
|
328
|
4.9
|
Using this data, we tried to prove that NH is a safer state to drive in the MA. In the t-tests performed, we hoped to see that fatal crashes and crash deaths were higher in MA than in NH.
Welch Two Sample t-test
data: car$Fatal.motor.vehicle.crashes[car$state == "NH"] and car$Fatal.motor.vehicle.crashes[car$state == "MA"]
t = -14.751, df = 13.021, p-value = 1.66e-09
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
-262.761 -195.639
sample estimates:
mean of x mean of y
113.7 342.9
In our initial testing, we compared the fatal motor vehicle crashes from 2005-2014 in the states of NH and MA to determine if the means of the two states were actually significant. The result of the p-value gives a percentage of if the result of the data is generated by random chance alone. With a lower p-value, under 5%, it shows that there is a significant difference between the data. With the means of NH being much lower than the means of MA, with a low p-value, it shows that there are a lot more crashes each year in MA than in NH.
Welch Two Sample t-test
data: car$Motor.vehicle.crash.deaths[car$state == "NH"] and car$Motor.vehicle.crash.deaths[car$state == "MA"]
t = -14.497, df = 12.866, p-value = 2.399e-09
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
-277.2982 -205.3018
sample estimates:
mean of x mean of y
122.7 364.0
With the second test being the crash deaths in NH and MA, with the t test showing a significant difference in means of 122.7 crash deaths in NH and 364 crash deaths in MA with a p-value of under 1%. This means the results are do not happen by random chance alone, showing there are much more crash deaths in MA than in NH each year.
Looking at the test results, it shows how MA has higher fatal crashes each year than in NH, meaning that in these cases, MA is worse to drive in than NH.
Would you also be able to look into the rate at which crashes are fatal in each state to compare the probabilities of death when in a car crash in each state, as while you stated there are more crash deaths in MA, could this just be due to the greater amount of total crashes in MA.
ReplyDeleteMaybe look into deaths/ per person in each state. The population of Massachusetts is much larger than the population of New Hampshire. Therefore, it is no surprise that thee are more deaths in Massachusetts, there are more people there to crash into. Maybe look into the ratio of deaths. Do more people die in New Hampshire per person of the population or do more people die in Massachusetts per person of the population.
ReplyDeletethere*
DeleteOn the table it says Fatal motor vehicle crashes and motor vehicle crash deaths. I think I know what the difference between the two is, but it is not very clear. Maybe you could explain the table before you explain the t-tests.
ReplyDeleteCan you investigate more about the causes of the crashes? Are Mass drivers actually bad drivers, or do they deal with worse conditions than NH drivers do?
ReplyDeleteIn your first paragraph you say, " there are a lot more crashes each year in MA than in NH." Is that overall crashes or just fatal ones?
ReplyDeleteYour final conclusion is "Looking at the test results, it shows how MA has higher fatal crashes each year than in NH, meaning that in these cases, MA is worse to drive in than NH." I am not sure if you can make this conclusion because there are a lot of other variables that are different in MA and NH. For instance, MA has a higher population, so it also likely has a greater number of drivers, which could influence the crash statistics, artificially inflating the crash rate in MA as compared to NH.
This may be hard to find out but could you find why there are more crashes and crash deaths in MA than in NH. Is it because they were taught differently or is it because there are more people and bigger cities or something like that. What is the most contributing factor?
ReplyDeleteThis may be hard to find out but could you find why there are more crashes and crash deaths in MA than in NH. Is it because they were taught differently or is it because there are more people and bigger cities or something like that. What is the most contributing factor?
ReplyDeleteI like the fact that you have a specific question you are trying to answer with this data. It is an interesting but sad data set. It would be interesting to compare the crashes in cities vs towns then look at the number of cities vs town in NH and MA. This could show why MA is higher than NH
ReplyDeleteIn terms of your question and trying to figure out which state is safer to drive in, try looking at the total amount of car crashes per year. While Massachusetts may have more deaths than New Hampshire, it's possible that there are more total accidents in New Hampshire. Just something to consider.
ReplyDeleteIt may also be interesting to look at how the number of traffic accidents and fatalities have changed from 2005-2014 in each state, maybe to make a conclusion about which has been taking more action to prevent accidents.
ReplyDeleteYour data is organized well and easy to interpret.