Answer:
Option a is right
Step-by-step explanation:
Given that as part of a research project on student debt at TWU, a researcher interviewed a sample of 35 students that were chosen at random concerning their monthly credit card balance.
Sample average = 2573
Variance = 4252
Sample size = 35
STd deviation of X =
Score of student selected at random X=1700
Corresponding Z score =
Rounding of we get Z score = -13.4
option a is right
Answer:
x ∈ (-∞, -1) ∪ (1, ∞)
Step-by-step explanation:
To solve this problem we must factor the expression that is shown in the denominator of the inequality.
So, we have:
So the roots are:
Therefore we can write the expression in the following way:
Now the expression is as follows:
Now we use the study of signs to solve this inequality.
We have 3 roots for the polynomials that make up the expression:
We know that the first two are not allowed because they make the denominator zero.
Observe the attached image.
Note that:
when
when
and
is always
Finally after the study of signs we can reach the conclusion that:
x ∈ (-∞, -1) ∪ (1, 2] ∪ [2, ∞)
This is the same as
x ∈ (-∞, -1) ∪ (1, ∞)
