Discussion Paper Assignment | Homework Help Websites
February 5th, 2019
1.
| Pretend you are asked to test the claim that the true mean weight of a ream of paper manufactured in your factory is different from 6.5 pounds. You will have a/an… | |
| a) | lower tail test |
| b) | upper tail test |
| c) | two tail test |
| d) | half tail test |
| e) | four tail test |
* 2.
| True or False: The null hypothesis can be proven if it is not rejected. |
| True False |
* 3.
| Let’s say we don’t know the population standard deviation and we are asked to create a 90% confidence interval. Our sample size is 2. Which value most accurately represents the critical value of “t” that you would use to plug in for your interval? | |
| a) | 6.314 |
| b) | 2.920 |
| c) | 3.078 |
| d) | 1.886 |
| e) | 1.638 |
4.
| Let’s say we know the population standard deviation and we are asked to create a 85% confidence interval. Which value most accurately represents the critical value of Z that you would use to plug in for your interval? | ||
| a) | 1.40 | |
| b) | 1.65 | |
| c) | 1.96 | |
| d) | 1.04 | |
| e) | 1.44 | |
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* 5.
| If you use the sample size equation and get a result of n=19.21, how many people should you sample? | |
| a) | 19.21 |
| b) | 14 |
| c) | 20 |
| d) | 1.96 |
| e) | 2.95 |
* 6.
| You are a manager at a firm and you believe your monthly costs have decreased. The costs have always been $9,000 but you now believe they are less and would like to test this claim. If you run a hypothesis test, which of the following statements would fit your problem? | |
| a) | You have an upper tail test |
| b) | Your alternative hypothesis could be stated as the population mean is less than 9,000 |
| c) | Your null hypothesis could be stated as the population mean is greater than or equal to 9,000. |
| d) | A, B, and C are correct |
| e) | Just B and C are correct |
* 7.
| True or False: When sub-populations vary considerably, it is advantageous to utilize cluster sampling to ensure that each sub-population gets some representation and thus sampling error is reduced. |
| True False |
* 8.
| Pretend you are in charge of a packaging equipment company that is filling boxes of cereal. From past experience we know the population’s mean weight of the filled boxes is 800 grams (and we know the distribution of grams is approximately normal). The population standard deviation is given as 24 grams. You are told to randomly select a sample of 100 boxes. You need to determine the probability that the sample of the 100 boxes will have a sample mean above the minimum allowed grams of 796. The probability will be between… | |
| a) | 0 and .10 |
| b) | .11 and .20 |
| c) | .21 and .40 |
| d) | .41 and .60 |
| e) | .61 and 1.0 |
* 9.
| Find the sample size: We desire to be within plus or minus .5 units. We will have a 95% confidence interval and the population standard deviation is 2. What is the estimated sample size? | |
| a) | the estimated sample size lies between 0 and 10 |
| b) | the estimated sample size lies between 11 and 20 |
| c) | the estimated sample size lies between 21 and 30 |
| d) | the estimated sample size lies between 31 and 40 |
| e) | the estimated sample size lies between 41 and 60 |
* 10.
| Let’s say we know the population standard deviation and we are asked to create a 99% confidence interval. Our sample size is 17. Which value most accurately represents the critical value of Z that you would use to plug in for your interval? | |
| a) | 2.57 |
| b) | 1.65 |
| c) | 1.96 |
| d) | 2.33 |
| e) | 1.44 |
* 11.
| True or False: The population standard deviation is 3. The sample size is 9. The sample mean is 27. .05 is your level of significance. The alternative hypothesis is that the population mean is >25, use your sample data to test this claim. If you use this information, you will reject the null hypothesis. |
| True False |
12.
| Find the sample size: We desire to be within plus or minus 50 units. We will have a 95% confidence interval and the population standard deviation is 100. What is the estimated sample size? | ||
| a) | the estimated sample size lies between 0 and 10 | |
| b) | the estimated sample size lies between 11 and 20 | |
| c) | the estimated sample size lies between 21 and 30 | |
| d) | the estimated sample size lies between 31 and 40 | |
| e) | the estimated sample size lies between 41 and 60 | |
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* 13.
| Let’s say we don’t know the population standard deviation and we are asked to create a 99% confidence interval. Our sample size is 7. Which value most accurately represents the critical value of “t” that you would use to plug in for your interval? | |
| a) | 3.499 |
| b) | 3.707 |
| c) | 3.143 |
| d) | 1.650 |
| e) | 2.998 |
* 14.
| Pretend you are asked to test the claim that the true mean weight of chocolate bars manufactured in a factory is more than 3 ounces. You will have a/an… | |
| a) | lower tail test |
| b) | upper tail test |
| c) | two tail test |
| d) | half tail test |
| e) | four tail test |
* 15.
| Pretend you are in charge of a packaging equipment company that is filling boxes of cereal. From past experience we know the population’s mean weight of the filled boxes is 300 grams (and we know the distribution of grams is approximately normal). The population standard deviation is given as 12 grams. You are told to randomly select a sample of 36 boxes. You need to determine the probability that the sample of the 36 boxes will have a sample mean below 301. The probability will be between… | |
| a) | 0 and .010 |
| b) | .011 and .043 |
| c) | .044 and .150 |
| d) | .151 and .222 |
| e) | .223 and 1.0 |
* 16.
| Determine the probability that a sample of 25 boxes will have a mean weight between 397 grams and 401 grams. Past records show that the population mean is 400 grams and the population standard deviation is 10. There will be ____________ probability that the sample is between 397 and 401. Select the closest possible answer to fill in the blank above. | |
| a) | approximately .20 |
| b) | approximately .40 |
| c) | approximately .60 |
| d) | approximately .80 |
| e) | approximately .100 |
17.
| A sampling distribution of the mean is a simple random sample where the sample size is selected at random. If, for instance, the randomly selected sample size is 7 you would take a sample of 7 observations and measure the mean to get your sampling distribution of the mean. | ||
| True False | ||
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* 18.
| In a simple random sample… | |
| a) | every possible sample has the same probability of being selected. |
| b) | every item has the same chance of being selected as every other item. |
| c) | the size of the sample is chosen at random |
| d) | a and b |
| e) | a and c |
* 19.
| True or False: If you had a 88.49% confidence interval planned, the critical value you would use would be 1.20. Understand that you are given the following information: you know the sample standard deviation is 6 and the sample size is 10. |
| True False |
20.
| True or False: When most of the variation is within a population and not between separate populations, it is advantageous to use stratified sampling over cluster sampling. | ||
| True False | ||
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