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).
So you know that 11 U.S. Dollars can be exchanged for 10 Euros which is 10/11. To figure out how many Euros you will receive for 1 Dollor you have to find the unit rate. To do this divide 10 by 11. The answer is 0.90
Allright to find this you have to put the equation into order again. The equation of a line is y=mx+c. M= Gradient. C = Y intercept. After you put it in order you just have to read it. If you need the answers comment ill find them...
Well, if you are asking how much is for each avocado, then what I did is I divided 27 by 12 and I got 2.25
