We are given the following data:
Sample Size = n = 1000
Sample Mean = u = 15 hours
Population Standard Deviation = s = 2 hours
Since we know the population standard deviation, we can use z distribution to find the confidence interval about the mean. z value for 95% confidence interval is 1.96.
Formula for the confidence interval is:

Using the values in the formula, we get:

Therefore, the 95% confidence interval about the population mean is 14.88 hours to 15.12 hours. So B option is the correct answer.
Answer:
266
Step-by-step explanation:
Answer:
11 3/5*9*12 1/2=1,305
1,305 cubic meters
Hope I helped.
Step-by-step explanation:
1. Check the prices of phones from different stores.
2. Do some research to see what is the average cost of the phone.
3. Check for possible discounts.
Hope this helps :)
9514 1404 393
Answer:
a, b, c --- all <em>not</em> representative
Step-by-step explanation:
The question posed by the engineer is "are residents of the city in favor of ...".
The only representative sample is one from a pool that includes <em>all residents of the city</em>—not just those who (a) use the road, (b) live along the road, or (c) own homes.
__
<em>Additional comment</em>
The engineer may want to refine the question. As posed, it would include children, homeless, and/or institutionalized residents of the city as well as drivers and tax-payers. In inclusive cultural traditions, "residents of the city" may also include animals, plants, water, air, and other holders of spiritual energy.