I am using R studio and wanted to be sure i am inputing the right formulas, than

Question

I am using R studio and wanted to be sure i am inputing the right formulas, thank you in advance.

ANOVA

(a) Load the data from chest.csv (4 points) (Note that this is a comma-separated file, so use the appropriate instruction. If you are having trouble uploading the data, type it in: one vector for temperatures and one for the factor context.) The data are chest deceleration measurements (in g, where g is the force of gravity) from samples of small, midsize and large cars.

(b) Find the mean and standard deviation of chest deceleration by groups. Does the equal standard deviation assumption for ANOVA appear to be satisfied? (8 points)

(c) Draw comparative boxplots (one boxplot for each size in the same plot). Do the boxplots support

equality of means? (4 points)

(d) Write the null and alternative hypotheses to test for equality of means. (2 points)

(e) Perform an ANOVA test at ? = 0.01 and state your conclusions (you do not have to perform posthoc

analysis). (6 points)

(f) Verify the P-value from part (e) using the pf command and finding the correct area for the Fdistribution

(2 points).

CAR SIZE CHEST Chev Aveo Small 44 Honda Civic Small 39 Mitsubishi Lancer Small 37 VW Jetta Small 54 Hyundai Elantra Small 39 Kia Rio Small 44 Subaru Impreza Small 42 Ford Fusion Midsize 36 Nissan Altima Midsize 53 Nissan Maxima Midsize 43 Honda Accord Midsize 42 Volvo S60 Midsize 52 VW Passat Midsize 49 Toyota Camry Midsize 41 Toyota Avalon Large 32 Hyundai Azera Large 45 Cadillac DTS Large 41 Lincoln Town Large 38 Dodge Charger Large 37 Merc Gr Marq Large 38 Buick Lucerne Large 33

Explanation / Answer

a)

## loading the data from text file
dataset_chegg<-read.csv("chegg.csv")

b)

library(tidyr)
library(dplyr)

Chest_group<-group_by(dataset_chegg,dataset_chegg$SIZE)
means<-summarise(Chest_group,mean(CHEST))
sd<-summarise(Chest_group,sd(CHEST))

c)

boxplot(dataset_chegg$CHEST~dataset_chegg$SIZE).

No it is not supporting equality of means

d)

HO: Mean of Chest is equal across different sizes.

Ha: Mean of chest is not equal across different sizes.

## Running one way ANOVA test
results <- aov(dataset_chegg$CHEST~as.factor(dataset_chegg$SIZE), data=dataset_chegg)
summary(results)

e)

P- value 0.06 > 0.05.

So we do not reject Ho.

So means of chest is same across different sizes

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.