Answer:
2.64
Step-by-step explanation:
The z score is calculated as
z=(x-mean)/Sd
The mean of scores of statistics exam=μ=99
The standard deviation of scores of statistics exam=σ=11
Individual's score in statistics exam=x=128
z=128-99/11=29/11=2.64
Hence, the z score of individual score is 2.64.
Answer: 7 and 23
Step-by-step explanation:
Let the first number be x and the second number be y.
From the first statement , we have
x + y = 30 --------------- equation 1
Taking x as the larger number , from the second statement , we have
x = 3y + 2 --------------- equation 2
substitute equation 2 into equation 1 , we have
3y + 2 + y = 30
4y + 2 = 30
4y = 28
y = 7
substitute y = 7 into equation 2 , we have
x = 3(7) + 2
x = 21 + 2
x = 23
therefore : x = 23 and y = 7
Concluimos que hay 8 libros de aritmética.
<h3>¿Cuántos libros de aritmética coloca la bibliotecaria?</h3>
Sabemos que la relacion entre el número de libros de aritmetica y el total de libros es de 4 a 9.
Es decir, sí el número total de libros es N, entonces (4/9)*N de esos libros son de aritmética.
Sea X el número de libros de aritmética. Sabemos que hay 10 libros de algebra, entonces el número total N es:
N = 10 + X
Y usando la relación de arriba, podemos escribir:
X = (4/9)*N = (4/9)*(10 + X)
Ahora podemos resolver esto para X.
X*(9/4) = 10 + X
X*(9/4) - X = 10
X*(5/4) = 10
X = (4/5)*10 = 8
Concluimos que hay 8 libros de aritmética.
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Answer:
C
Step-by-step explanation: