Question

Can somebody explain to me stem and leaf diagrams please?

Answer 1

They are a method for showing the frequency of a data plot in a much more compact and numerical way.  

1[2 3
2[1 7
3[3 4 5 7 
4[ 0 0 1

Key 1[2= 12

meaning that 3[5 is 35 and 4[0 is 40 and so and so forth