Module 9 Assignment

Daniel Tafmizi

Lis 4273

Dr. Ajani 

March 10, 2024

Module 9 Assignment

# 1.

#Your data.frame is

assignment_data <- data.frame( Country = c("France","Spain","Germany","Spain","Germany", "France","Spain","France","Germany","France"), age = c(44,27,30,38,40,35,52,48,45,37), salary = c(6000,5000,7000,4000,8000), Purchased=c("No","Yes","No","No","Yes", "Yes","No","Yes","No","Yes"))

#Generate simple table in R that consists of four rows: Country, age, salary and purchased.

install.packages("data.table")       

library(data.table)

table <- setDT(assignment_data) #turns data frame into table

table

Country   age salary Purchased

    <char> <num>  <num>    <char>

1:  France    44   6000        No

2:   Spain    27   5000       Yes

3: Germany    30   7000        No

4:   Spain    38   4000        No

5: Germany    40   8000       Yes

6:  France    35   6000       Yes

7:   Spain    52   5000        No

8:  France    48   7000       Yes

9: Germany    45   4000        No

10:  France    37   8000      Yes

#2. Generate contingency table also know as rx C table using mtcars dataset.

assignment9 <- table(mtcars$gear, mtcars$cyl, dnn=c("gears"))

                                                     

# 2.1 Add the addmargins() function to report on the sum totals of the rows and columns of assignment9 table 

 

addmargins(assignment9) # table aligns cars with gears 3,4,or 5 and cyl 4,6, or 8.

gears  4  6  8 Sum

3      1  2 12  15

4      8  4  0  12

5      2  1  2   5

Sum   11  7 14  32

                                                     

2.2 Add prop.tables() function, and report on the proportional weight of each value in a assignment9 table

prop.table(assignment9) 

gears       4       6       8

3       0.03125 0.06250 0.37500

4       0.25000 0.12500 0.00000

5       0.06250 0.03125 0.06250

# calculates the proportion of each cell by the sum of all cells. Allows us to see what most car cyl and gear amount combinations are.

# Most common combination is 8 cyl with 3 gears, followed by 4 cyl 4 gears

# Least common combination is 8 cyl with 4 gears, followed by 4 cyl 3 gears and 6 cyl 5 gears(that's what I drive :)

                                                     

2.3 Add margin = 1 to the argument under prop.table() function, and report on the row proportions found in assignment9 table.

prop.table(assignment9, margin = 1)  

gears          4          6          8

3        0.06666667 0.13333333 0.80000000

4        0.66666667 0.33333333 0.00000000

5        0.40000000 0.20000000 0.40000000

#calculates the proportion of each cell by the sum of its row.

# This allows us to easily see which cylinder amount is most common with each gear amount.

# Cars with three gears use 8 cyl, 6 cyl, 4 cyl in descending order

# Cars with four gears use 4 cyl, 6 cyl in descending order

# Cars with 5 gears use 8 or 4 cyl, 6 cyl in descending order