Question

A water treatment plant needs to maintain the pH of the water in the reservoir at a certain level. To monitor this, they take 2 oz. of water at 37 locations every hour, measure the pH at each of those locations, and find their average. If the pH level of the reservoir is ok, the results at each location will have varying results, with an average pH of 8.5 and a standard deviation of 0.22. If the pH level of the reservoir is ok, what is the probability that the sample average is MORE than 8.47?A.-0.833 B.0.2033 C.0.7967 D.-0.14 E.0.4443 F.0.5557

Answer 1

Answer:

C.) 0.7967

Explanation:

Hello,

Normal distribution is used here as:

$z=\frac{pH_{sample}-pH_{av}}{stand_{dev}*\sqrt{n} }$

In this case, the sample's pH is 8.47, the average pH 8.5, standard deviation 0.22 and sample size 37, thus:

$z= \frac{8.47-8.5}{0.22/\sqrt{37} }\\z=-0.8295$

Now, based on the table for standard normal distribution which comes from a symmetric bell-like graph, the probability is 0.797 which matched with the C answer.

Best regards.

Answer 2

The branch of science that deals with chemicals and bonds are called chemistry.  According to the question, the ph will depend on the amount of proton ion in the solution

The correct answer is C.

PH

• The Ph value is defined as the amount of solute present in the solution which describes the concentration of the fluid.
• According to the question, the ph of water treatment is as follows:-
• The formula used to solve the question is,
• $z =\frac{Ph_{sample} - Ph_{ave}}{stand_{deviation}*\sqrt{n} }$

All the value is given in the question, the value is as follows:-

• Sample's pH is 8.47,
• Average pH 8.5,
• Standard deviation 0.22  
• Sample size 37

Placed the value in the equation and solve it.

$z =\frac{8.47 -8.5}{\frac{22}{\sqrt{37} } }$

The value of Z is -0.8295

In the table for standard normal distribution which comes from the asymmetric bell-like graph, the probability is 0.797 which is matched with the C answer.

Hence, the correct answer is C that is 0.797.

For more information about the Ph, refer to the link:-

https://brainly.com/question/491373