week-8-practice-quiz-with-explanation

1. Award: 10 out of 10.00 points 2. Award: 10 out of 10.00 points Score: 212.50/230 Points 92.39 % Classify the situation as stratified random sampling, systematic random sampling, or cluster sampling. A college decided to survey its students to see how they felt about using a computer in all classes, and how much extra tuition they would be willing to pay for the service. The college made a list of all of the classes registered in the semester and then randomly selected 25 classes. All students in the selected 25 classes were surveyed. The situation is classified as cluster sampling. References Worksheet Learning Objective: 07-02 Define sampling error. Classify the situation as stratified random sampling, systematic random sampling, or cluster sampling. A college decided to survey its students to see how they felt about using a computer in all classes, and how much extra tuition they would be willing to pay for the service. The college made a list of all of the classes registered in the semester and then randomly selected 25 classes. All students in the selected 25 classes were surveyed. The situation is classified as cluster sampling. Classify the situation as stratified random sampling, systematic random sampling, or cluster sampling. A college decided to survey its students to see how they felt about using a computer in all classes, and how much extra tuition they would be willing to pay for the service. The college determined that of its 10,000 students, 500 surveys would be sufficient to achieve satisfactory results. The students attending in that semester were sorted according to their student number, and every 20th student on the list was selected for the survey. The situation is classified as systematic random sampling. References Worksheet Learning Objective: 07-02 Define sampling error. Classify the situation as stratified random sampling, systematic random sampling, or cluster sampling. A college decided to survey its students to see how they felt about using a computer in all classes, and how much extra tuition they would be willing to pay for the service. The college determined that of its 10,000 students, 500 surveys would be sufficient to achieve satisfactory results. The students attending in that semester were sorted according to their student number, and every 20th student on the list was selected for the survey. The situation is classified as systematic random sampling.

3. Award: 10 out of 10.00 points Classify the situation as stratified random sampling, systematic random sampling, or cluster sampling. A college decided to survey its students to see how they felt about using a computer in all classes, and how much extra tuition they would be willing to pay for the service. The college decided to survey the students according to their programs of study. A random sample was selected from each program. The situation is classified as stratified random sampling. References Worksheet Learning Objective: 07-02 Define sampling error. Classify the situation as stratified random sampling, systematic random sampling, or cluster sampling. A college decided to survey its students to see how they felt about using a computer in all classes, and how much extra tuition they would be willing to pay for the service. The college decided to survey the students according to their programs of study. A random sample was selected from each program. The situation is classified as stratified random sampling.

4. Award: 10 out of 10.00 points A population consists of the following five values: 12, 12, 14, 15, and 20. a. Not available in Connect. b. By listing all samples of size 3, compute the mean of the distribution of the sample mean and the population mean. Compare the two values. (Round the final answers to 2 decimal places.) Sample means 14.60 Population mean 14.60 Both means are equal c. Compare the dispersion in the population with that of the sample means. Hint : Use the range as measure of dispersion. The dispersion of the population is greater than that of the sample means. References Worksheet Learning Objective: 07-02 Define sampling error. A population consists of the following five values: 12, 12, 14, 15, and 20. a. Not available in Connect. b. By listing all samples of size 3, compute the mean of the distribution of the sample mean and the population mean. Compare the two values. (Round the final answers to 2 decimal places.) Sample means 14.60 ± 0.01 Population mean 14.60 ± 0.01 Both means are equal c. Compare the dispersion in the population with that of the sample means. Hint : Use the range as measure of dispersion. The dispersion of the population is greater than that of the sample means. Explanation: b. Samples Values Sum Mean 1 12,12,14 38 12.67 2 12,12,15 39 13.00 3 12,12,20 44 14.67 4 14,15,20 49 16.33 5 12,14,15 41 13.67 6 12,14,15 41 13.67 7 12,15,20 47 15.67 8 12,15,20 47 15.67 9 12,14,20 46 15.33 10 12,14,20 46 15.33 μ = (12 + 12 + 14 + 15 + 20)/5 = 14.6 c. The dispersion of the population is greater than that of the sample means. The sample means vary from 12.67 to 16.33, whereas the population varies from 12 to 20.

5. Award: 10 out of 10.00 points A population consists of the following five values: 0, 0, 1, 3 and 6. a. Not available in Connect. b. By listing all samples of size 3, compute the mean of the distribution of the sample mean and the population mean. Compare the two values. (Round the final answer to the nearest whole number.) Sample means 2 Population mean 2 Both means are equal c. Compare the dispersion in the population with that of the sample means. Hint : Use the range as measure of dispersion (Round the final answers to two decimal places.) The dispersion of the population is greater than the sample means. The sample means vary from 0.33 to 3.33 , the population varies from 0 to 6 . References Worksheet Learning Objective: 07-02 Define sampling error. A population consists of the following five values: 0, 0, 1, 3 and 6. a. Not available in Connect. b. By listing all samples of size 3, compute the mean of the distribution of the sample mean and the population mean. Compare the two values. (Round the final answer to the nearest whole number.) Sample means 2 Population mean 2 Both means are equal c. Compare the dispersion in the population with that of the sample means. Hint : Use the range as measure of dispersion (Round the final answers to two decimal places.) The dispersion of the population is greater than the sample means. The sample means vary from 0.33 ± 0.01 to 3.33 ± 0.01 , the population varies from 0 to 6 . Explanation: b. Samples Values Sum Mean 1 0,0,1 1 0.33 2 0,0,3 3 1.00 3 0,0,6 6 2.00 4 0,1,3 4 1.33 5 0,3,6 9 3.00 6 0,1,3 4 1.33 7 0,3,6 9 3.00 8 1,3,6 10 3.33 9 0,1,6 7 2.33 10 0,1,6 7 2.33 μ = (0 + 0 + 1 + 3 + 6)/5 = 2

6. Award: 10 out of 10.00 points Given below are the last four digits of 18 random phone numbers of your local population. 9331 9618 1796 1631 3612 3750 1238 6117 8713 2933 4492 7671 2089 8296 7391 7688 2858 9654 a. Not available in Connect. b-1. Fill in the frequency table of the final digit of 18 randomly selected phone numbers. Digit Frequency 0 1 1 4 2 2 3 2 4 1 5 0 6 2 7 1 8 4 9 1 b-2. Using the sample mean of the final four digits (9331 would lead to a mean of 4), compute the mean of the sample means. (Round the final answer to 2 decimal places.) Mean of the sample means 4.81 c. Not available in Connect. References Worksheet Learning Objective: 07-03 Construct a sampling distribution of the sample mean. Given below are the last four digits of 18 random phone numbers of your local population. 9331 9618 1796 1631 3612 3750 1238 6117 8713 2933 4492 7671 2089 8296 7391 7688 2858 9654 a. Not available in Connect. b-1. Fill in the frequency table of the final digit of 18 randomly selected phone numbers. Digit Frequency 0 1 1 4 2 2 3 2 4 1 5 0 6 2 7 1 8 4 9 1 b-2. Using the sample mean of the final four digits (9331 would lead to a mean of 4), compute the mean of the sample means. (Round the final answer to 2 decimal places.) Mean of the sample means 4.81 ± 0.02 c. Not available in Connect.