1(x-2)= -5.5 solving for x. What's the answer
1 answer:
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Answer:
B) A one-sample t-test for population mean would be used.
Step-by-step explanation:
The complete question is shown in the image below.
The marketing executive is interested in comparing the mean number of sales of this year to that of previous year.
The marketing executive already has the value of mean from previous year and uses a sample to calculate the mean and standard deviation of sales for the current year.
Since, data is being collected for one sample only this limits us to chose between one sample test for mean. So now the possible options are one sample t-test for population mean and one sample t-test for population mean.
If we read the statement we can see that we have the value of sample mean and sample standard deviation. Value of population standard deviation is unknown. In cases where value of population standard deviation is not known and sample standard deviation is given, t-test is used.
Therefore, we can conclude that A one-sample t-test for population mean would be used.
Answer:
all real numbers less than or equal to 4
Step-by-step explanation:
To obtain the range we require the value of the y- coordinate of the vertex.
Given
f(x) = - (x + 5)(x + 1) ← equate f(x) to zero to find the zeros, that is
- (x + 5)(x + 1) = 0
Equate each factor to zero and solve for x
x + 5 = 0 ⇒ x = - 5
x + 1 = 0 ⇒ x = - 1
The vertex lies on the axis of symmetry which is at the midpoint of the zeros
=
=
= - 3
Substitute x = - 3 into f(x) for y- coordinate of vertex
= - (- 3 + 5)(- 3 + 1) = - (2)(- 2) = 4
The vertex = (- 3, 4 )
and - (x + 5)(x + 1) = - (x² + 6x + 5) = - x² - 6x - 5
Since the coefficient of the x² term is - 1 < 0
then the vertex is a maximum ∩
Hence range is [ 4, - ∞ )
That is all real numbers less than or equal to 4