Question

1.) Listed below are the number of deaths in the United States resulting from motor vehicle crashes.

a.) Create a scatterplot in StatCrunch and draw a sketch of it. Make sure to label the x and y axis.

b.) Find the correlation coefficient, rounded to four decimal places.

c.) Find the equation of the line of best fit.

d.) Is the correlation significant? Explain why or why not.

e.) Predict the number of deaths from motor vehicle crashes in 2015.

f.) In 2015 there were actually 32,999 deaths from motor vehicle crashes. Is your above estimate close to the actual result?

g.) Predict the number of deaths from motor vehicle crashes in 2140. Is this result reasonable?

Year 1975 1980 1985 1990 1995 2000 2005 2010

Deaths 44,525 51,091 43,825 44,599 41,817 41,945 43,443 32,708

Answer 1

Please find R code for the same

yr=c(1975,1980,1985,1990,1995,2000,2005,2010)
deaths=c(44525,51091,43825,44599,41817,41945,43443,32708)
plot(yr,deaths,main="Deaths from Motor vehicle crashes",xlab = "Year",ylab = "No of deaths")
fit=lm(deaths~yr)
cor(yr,deaths)
fit$coefficients
d2015=656783.75-308.05*2015
d2040=656783.75-308.05*2140

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b) The correlation coeficient is coming out to be -0.7447129

C) The line of best fit is, Deaths = 656783.75 - 308.05 * Years

D) The coorelation is significant because it is more than 0.5. Corrrealation coefts tells s the measre of linear relationship

e) Predicted No of deaths from motor vehicles in 2015 are 656783.75-308.05*2015 = 36063

f) Actaual deaths from motor vehicles in 2015 are 32999 it is moderately close to predcited value

g) Predicted No of deaths from motor vehicles in 2140 are" - 2443.25

It is not reasonable since deaths can never be negative