The document analyzes student achievement data from a file with 20 observations. It calculates the frequency of each achievement level (A, D, E, I, S), the percentage of students in each level, the cumulative frequency, and cumulative percentage. The results are combined into a single table with the frequency, percentage, cumulative frequency, and cumulative percentage for each achievement level.

1. > datos=read.table("logros.txt")
> attach(datos)
> datos
V1
1 A
2 A
3 A
4 A
5 A
6 S
7 S
8 S
9 S
10 S
11 D
12 D
13 D
14 D
15 I
16 I
17 I
18 E
19 E
20 E
> f=table(datos)
> f
datos
A D E I S
5 4 3 3 5
> n=sum(f)
> n
[1] 20
> h=(f/n)*100
> h
datos
A D E I S
25 20 15 15 25
> F=cumsum(f)
> F
A D E I S
5 9 12 15 20
> H=cumsum(h)
> H
A D E I S
25 45 60 75 100
> cbind(f,h,F,H)
f h F H
A 5 25 5 25
D 4 20 9 45
E 3 15 12 60
I 3 15 15 75
S 5 25 20 100
>