Question

Using program R, please help solve:
(if answered by Tuesday 6/11 evening, I will rate)

3.32 The data set UScereal (MASS) contains information about cereals on a shelf of a United States grocery store. Make a table showing the relationship between manufacturer, mfr, and shelf placement, shelf. Are there any obvi ous differences between manufacturers?

Answer 1

ANSWER:

Given that,

we can fit a one way anova to see whats going on , the complete r snippet is as follows

library("MASS")

data.df <- data.frame(UScereal)

fit <- aov(lm(shelf~ mfr,data=data.df))
summary(fit)

table(data.df$mfr,data.df$shelf)

# plots

boxplot(data.df$shelf~data.df$mfr, data=data.df,
ylab="Values", main="Boxplots of the Data",col=c(3:9))

###################

The results are

> summary(fit)
Df Sum Sq Mean Sq F value Pr(>F)
mfr 5 4.97 0.9946 1.461 0.216
Residuals 59 40.17 0.6808   
> table(data.df$mfr,data.df$shelf)

1 2 3
G 6 7 9
K 4 7 10
N 2 0 1
P 2 1 6
Q 0 3 2
R 4 0 1

Boxplots of the Data G K P R Z 0Z Values

as can be seen from the table and the boxpolt , manfucturer G and K get the largest share of the shelves.