Answer: The margin of error = 3.71, confidence interval = (354.04, 361.46) and it means that mean cost is lies within the confidence interval.
Step-by-step explanation:
Since we have given that
Sample size = 400
Mean = $357.75
Standard deviation = $37.89
At 95% confidence level, z = 1.96
We first find the margin of error.
Margin of error is given by

95% confidence interval would be

Hence, the margin of error = 3.71, confidence interval = (354.04, 361.46) and it means that mean cost is lies within the confidence interval.
Answer:
1) (2,4)
2) (5,-2)
Step-by-step explanation:
those are the points at which the lines cross making them the solutions to the equations

+

equals

.
First, simplify

to

and also

to

. Your problem should look like:

+

.
Second, find the least common denominator of

and

to get 9.
Third, make the denominators the same as the least common denominator (LCD). Your problem should look like:

+

.
Fourth, simplify to get the denominators the same. Your problem should look like:

+

.
Fifth, join the denominators. Your problem should look like:

.
Sixth, simplify. Your problem should look like:

, which is the answer.
This is a quadratic equation, which is also a polynomial. Polynomials all have the domain (-infinity, +infinity).
As for the range: You can see from the graph that the smallest y-value is -2. Thus, the range is [-2, infinity).
Vas happenin!
Hope your day is going well
I think it’s A
Sorry if it’s wrong
Hope this helps *smiles*