Dataset

data()

library(psych)
mydata <- force(sat.act)

head(mydata)

##       gender education age ACT SATV SATQ
## 29442      2         3  19  24  500  500
## 29457      2         3  23  35  600  500
## 29498      2         3  20  21  480  470
## 29503      1         4  27  26  550  520
## 29504      1         2  33  31  600  550
## 29518      1         5  26  28  640  640

summary(mydata)

##      gender        education          age             ACT       
##  Min.   :1.000   Min.   :0.000   Min.   :13.00   Min.   : 3.00  
##  1st Qu.:1.000   1st Qu.:3.000   1st Qu.:19.00   1st Qu.:25.00  
##  Median :2.000   Median :3.000   Median :22.00   Median :29.00  
##  Mean   :1.647   Mean   :3.164   Mean   :25.59   Mean   :28.55  
##  3rd Qu.:2.000   3rd Qu.:4.000   3rd Qu.:29.00   3rd Qu.:32.00  
##  Max.   :2.000   Max.   :5.000   Max.   :65.00   Max.   :36.00  
##                                                                 
##       SATV            SATQ      
##  Min.   :200.0   Min.   :200.0  
##  1st Qu.:550.0   1st Qu.:530.0  
##  Median :620.0   Median :620.0  
##  Mean   :612.2   Mean   :610.2  
##  3rd Qu.:700.0   3rd Qu.:700.0  
##  Max.   :800.0   Max.   :800.0  
##                  NA's   :13