Question

2 Homework 1 1. In an experiment to investigate the effect of color of paper (blue, green, orange) on response rates for questionnaires distributed by the "wind shield method" in supermarket parking lots, 15 representative super- market parking lots were chosen in a metropolitan area and each color was assigmed at random to five of the lots. The response rates (in per- cent) are recorded in CH16PRO8.txt. The first column contains the response. In the second column, "1", "", and "3" represent the color blue, green, and orange respectively. Third column represents the lot umber Create a box plot of the data separating the results by color Does it appear there are differences in the response rates? Calculate the mean and standard deviation of the response rate for each of the three colors. Do the means appear to be the same? Do the standard deviations appear to be the same?

Answer 1

Question 1:

R Code for the boxplot:

#Importing Data
df <- read.table("http://users.stat.ufl.edu/~rrandles/sta4210/Rclassnotes/data/textdatasets/KutnerData/Chapter%2016%20Data%20Sets/CH16PR08.txt")
names(df) <- c("response", "color", "lot")

#Boxplot
library(ggplot2)
ggplot(df, aes(x = color, y = response, group = color)) +
geom_boxplot()

Question 2:

Yes, we can clearly see that there are differences in response as the colour changes.

Question 3:

library(dplyr)
summary_df <- df %>%
group_by(color) %>%
summarize(mean = mean(response),
standard_deviation = sd(response))

So the mean and standard deviation are not same.

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