Read my data:

sample_data = read.csv("sample_data.csv")

Summarize:

summary(sample_data)
##        X          group       value       
##  Min.   :  1.00   a:100   Min.   : 5.005  
##  1st Qu.: 50.75   b:100   1st Qu.: 9.796  
##  Median :100.50           Median :12.010  
##  Mean   :100.50           Mean   :11.919  
##  3rd Qu.:150.25           3rd Qu.:13.907  
##  Max.   :200.00           Max.   :19.288

Plot:

boxplot(value ~ group, sample_data)