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bagirrra123 [75]
3 years ago
11

The water department checks the city water supply on a regular basis for contaminants such as xylenes. the water department take

s 200 samples and estimates that the concentration of xylenes in your drinking water is 3.5 ppb (parts per billion), with a standard deviation of 0.2 ppb.
assuming the samples were random and unbiased, how much confidence can you have in this data?

Mathematics
1 answer:
Novosadov [1.4K]3 years ago
6 0

Answer:

Its A

Step-by-step explanation:

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Which set of coordinate pairs do NOT represent a linear function?
White raven [17]

Answer:

I'm pretty sure it is the second one

Step-by-step explanation:

7 0
3 years ago
A school has 3400 students. They conduct a random sample of 124 students and find that 38 of them hate the school.
Contact [7]

Answer:

a) We need a sample size of at least 2401.

b) We need a sample size of at least 1936.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.

In which

z is the zscore that has a pvalue of .

The margin of error is:

95% confidence level

So , z is the value of Z that has a pvalue of , so .

(a) you are unwilling to predict the proportion value at your school and​

We use , which is when we are going to need the largest sample size.

So we need to find We need a sample size of at least 2401.

(b) you use the results from the surveyed school as a guideline.

Now the same calculation, just with . So

We need a sample size of at least 1936.

5 0
3 years ago
Solve the equation: 3x-1/5-2/9x=124/5
Inessa [10]

Answer:

x=9

Step-by-step explanation:

3 0
2 years ago
Is the answer A ?????<br><br> I don't know, plzzzz help me
-Dominant- [34]
I think very well that it is A or B. With my experience, but you might want to keep doing research.

8 0
3 years ago
Read 2 more answers
Anthony rolled a six-sided die 138 times. Predict how many times you expect the die to have rolled on a 6?
Crazy boy [7]

Answer:

It can be 23 or 823

Step-by-step explanation:

Depends because if you divide 138 and 6 you'll get 23.

If you multiply 138 times 6 you'll get 823  

6 0
3 years ago
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