> students = c("Chloe","Muhammed","Holden")
> beer=c(0.25,3,7)
> d=data.frame(students,beer)
> d
  students beer
1    Chloe 0.25
2 Muhammed 3.00
3   Holden 7.00
> summary(d)
     students      beer      
 Chloe   :1   Min.   :0.250  
 Holden  :1   1st Qu.:1.625  
 Muhammed:1   Median :3.000  
              Mean   :3.417  
              3rd Qu.:5.000  
              Max.   :7.000  
> t.test(d$beer)

        One Sample t-test

data:  d$beer
t = 1.7435, df = 2, p-value = 0.2234
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
 -5.015081 11.848415
sample estimates:
mean of x 
 3.416667 

> ?t.test
starting httpd help server ... done
> t.test(d$beer,mu=3.5,alternative="greater")

        One Sample t-test

data:  d$beer
t = -0.042524, df = 2, p-value = 0.515
alternative hypothesis: true mean is greater than 3.5
95 percent confidence interval:
 -2.30552      Inf
sample estimates:
mean of x 
 3.416667 

> sd(d$beer)
[1] 3.394235
> mean(d$beer)
[1] 3.416667

> # test stat
> t = (mean(d$beer)-3.5)/(sd(d$beer)/sqrt(3))
> t
[1] -0.04252433

> hist(d$beer)