tablas estadísticas 3 eso

1. 1
ACTIVIDAD NÚMERO 5
Completa los datos que faltan en las tablas estadísticas siguientes:
TABLA I
Calificación n(xi) f(xi)
Insuficiente a 0.375
Suficiente 20 c
Notable 16 d
Sobresaliente b e
Total 80 Σ f(xi)
RESOLUCIÓN:
f(xi) =
N
xn i )(
→
80
a
= 0.375 → a = 80 · 0.375 = 30
b = 80 - (16 + 20 + 30) = 14
c = 20/80 = 0.25
d = 16/80 = 0.2
e = 14/80 = 0.175
Σ f(xi) = 1
SOLUCIÓN FINAL:
Calificación n(xi) f(xi)
Insuficiente 30 0.375
Suficiente 20 0.250
Notable 16 0.200
Sobresaliente 14 0.175
Total 80 1
TABLA II
Número de
caries
n(xi) f(xi)
0 25 0.25
1 20 0.2
2 a d
3 15 0.15
4 b 0.05
Total c e
RESOLUCIÓN:
f(xi) =
N
xn i )(
→
c
25
= 0.25 →
25.0
25
= c → c = 100
100
b
= 0.05 → b = 0.05 · 100 = 5
a = 100 - (25 + 20 + 15 + 5) = 35
e = 1
d = a/c → d = 35/100 → d = 0.35
SOLUCIÓN FINAL:
Número de caries n(xi) f(xi)
0 25 0.25
1 20 0.20
2 35 0.35
3 15 0.15
4 5 0.05
Total 100 1

2. 2
TABLA III
Número de
hijos
n(xi) f(xi)
0 a 0.2
1 15 d
2 b e
3 5 f
4 4 g
5 c 0.02
Total 50 Σ f(xi)
RESOLUCIÓN:
f(xi) =
N
xn i )(
→
50
a
= 0.2 → a = 50 · 0.2 = 10
f(xi) =
N
xn i )(
→
50
c
= 0.02 → c = 50 · 0.02 = 1
b = 50 - (10 + 15 + 5 + 4 + 1)
b = 50 - (10 + 15 + 5 + 4 + 1)
b = 15
d = 15/50 = 0.3
e = 15/50 = 0.3
f = 5/50 = 0.1
g = 4/50 = 0.08
Σ f(xi) = 1
SOLUCIÓN FINAL:
Número de hijos n(xi) f(xi)
0 10 0.20
1 15 0.30
2 15 0.30
3 5 0.10
4 4 0.08
5 1 0.02
Total 50 1.00
TABLA IV
xi n(xi) N(xi) f(xi)
1 3 d h
2 4 e i
3 a 16 0.15
4 7 f j
5 5 28 k
6 b 38 l
7 7 45 ll
8 c g m
RESOLUCIÓN:
a = 9 ya que N(xi) = 16 (16 – 4 – 3 = 9)
f = 23 ya que N(xi) = 16 y n(xi) = 7
b = 10 ya que N(xi) = 38 y N(xi -1) = 28
f(xi) =
N
xn i )(
→
N
a
= 0.15 →
N =
15.0
a
=
15.0
9
= 60

3. 3
c = 60 - (3 + 4 + 9 + 7 + 5 + 10 + 7) = 60 - 45 = 15
d = 3 ; e = 7 ; g = 60
h = 3/60 = 0.05 ; i = 4/60 = 0.07
j = 7/60 = 0.12 ; k = 5/60 = 0.08
l = 10/60 = 0.17 ; ll = 7/60 = 0.12
m = 15/60 = 0.25
SOLUCIÓN FINAL:
xi n(xi) N(xi) f(xi)
1 3 3 0.05
2 4 7 0.07
3 9 16 0.15
4 7 23 0.12
5 5 28 0.08
6 10 38 0.17
7 7 45 0.12
8 15 60 0.25