13.)

a.)

library(ISLR2)

#Numerical Summary
summary(Weekly)
##       Year           Lag1               Lag2               Lag3         
##  Min.   :1990   Min.   :-18.1950   Min.   :-18.1950   Min.   :-18.1950  
##  1st Qu.:1995   1st Qu.: -1.1540   1st Qu.: -1.1540   1st Qu.: -1.1580  
##  Median :2000   Median :  0.2410   Median :  0.2410   Median :  0.2410  
##  Mean   :2000   Mean   :  0.1506   Mean   :  0.1511   Mean   :  0.1472  
##  3rd Qu.:2005   3rd Qu.:  1.4050   3rd Qu.:  1.4090   3rd Qu.:  1.4090  
##  Max.   :2010   Max.   : 12.0260   Max.   : 12.0260   Max.   : 12.0260  
##       Lag4               Lag5              Volume            Today         
##  Min.   :-18.1950   Min.   :-18.1950   Min.   :0.08747   Min.   :-18.1950  
##  1st Qu.: -1.1580   1st Qu.: -1.1660   1st Qu.:0.33202   1st Qu.: -1.1540  
##  Median :  0.2380   Median :  0.2340   Median :1.00268   Median :  0.2410  
##  Mean   :  0.1458   Mean   :  0.1399   Mean   :1.57462   Mean   :  0.1499  
##  3rd Qu.:  1.4090   3rd Qu.:  1.4050   3rd Qu.:2.05373   3rd Qu.:  1.4050  
##  Max.   : 12.0260   Max.   : 12.0260   Max.   :9.32821   Max.   : 12.0260  
##  Direction 
##  Down:484  
##  Up  :605  
##            
##            
##            
## 
#Graphical Summary
pairs(Weekly)

#Subset the numeric columns 
numeric_cols <- c("Lag1", "Lag2", "Lag3", "Lag4", "Lag5", "Volume", "Today")

cor_matrix <- cor(Weekly[, numeric_cols])

cor_matrix
##                Lag1        Lag2        Lag3         Lag4         Lag5
## Lag1    1.000000000 -0.07485305  0.05863568 -0.071273876 -0.008183096
## Lag2   -0.074853051  1.00000000 -0.07572091  0.058381535 -0.072499482
## Lag3    0.058635682 -0.07572091  1.00000000 -0.075395865  0.060657175
## Lag4   -0.071273876  0.05838153 -0.07539587  1.000000000 -0.075675027
## Lag5   -0.008183096 -0.07249948  0.06065717 -0.075675027  1.000000000
## Volume -0.064951313 -0.08551314 -0.06928771 -0.061074617 -0.058517414
## Today  -0.075031842  0.05916672 -0.07124364 -0.007825873  0.011012698
##             Volume        Today
## Lag1   -0.06495131 -0.075031842
## Lag2   -0.08551314  0.059166717
## Lag3   -0.06928771 -0.071243639
## Lag4   -0.06107462 -0.007825873
## Lag5   -0.05851741  0.011012698
## Volume  1.00000000 -0.033077783
## Today  -0.03307778  1.000000000