Answer:
Critical value: 
The 90% confidence interval for the population mean bromide concentration is (0.376, 0.39).
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so
. This value of z is the critical value
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the mean subtracted by M. So it is 0.383 - 0.0066 = 0.376 cc/cubic meter
The upper end of the interval is the mean added to M. So it is 0.383 + 0.0066 = 0.39 cc/cubic meter
The 90% confidence interval for the population mean bromide concentration is (0.376, 0.39).
Nope but I respect what you are
Answer:
Graph has been shown in the attached file.
Step-by-step explanation:
We have been given the system of equations

Both the equation represents a straight lines. We can find the x and y intercepts of these lines to graph.
The intercept form of a line is given by

Here a is the x - intercept and b is the y-intercept.
Divide both sides of the equation (1) by 16

Hence, x-intercept = 4 and the point is (4,0)
y-intercept = 4 and the point is (0,4)
Similarly, for the second line
Divide both sides of the equation (2) by -6

x-intercept = -6 and the point is (-6,0)
y-intercept = -1 and the point is (0,-1)
We'll plot these points in the xy- plane and then join to get the graph of these lines.
Try using a site like Khan Academy to get a solution
Answer:
18
Step-by-step explanation:
6*2=12
9*2=18
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