Q1. What are the approaches used in probability sampling and nonprobability sampling? Describe ALL of them in detail. In particular, explain the difference between cluster sampling, stratied sampling and quota sampling. Q2. What are the errors that happen in the sampling process? Describe each of them in detail and explain why they occur. Q3. Researchers are concerned about the impact of students working while they are enrolled in classes, and they'd like to know if students work too much and therefore are spending less time on their classes than they should be. First, the researchers need to nd out, on average, how many hours per week students are working. They know from previous studies that the standard deviation of this variable is about 5 hours. A survey of 200 students provides a sample mean of 7.10 hours worked. a} What is a 99% condence interval for the average hours that students work per week based on this sample? b) How do you interpret the result of Part a) into words? c) Compared to using the sample mean directly, what is the advantage of constructing a condence interval for the average hours that students work per week? Q4. You work for a research group who aim to study whether the amount of time Penn State students spent watching YouTube is signicantly differs from 10 hours per week. A sample of 50 Penn State students is selected, and each student is asked how many hours per week they watch YouTube. You nd the mean number of hours that the students in this sample spent watching YouTube is 11 hours per week, with an estimated standard deviation of 3. a} What type of hypothesis test should be adopted? Please state your null hypothesis and alternative hypothesis. b) Calculate the t-test statistic. Assume the signicance level is .05, what is the p-value? (Hint: use h_ttps://www.socscistatistics.com/pvalues/ r: to nd the p-value) What statistical decision will you make based on the p-value. The leader of the research group proposes to examine whether the female students spend the same time watching YouTube as the male students. In this sample, 25 are females and 25 are males. The mean number of hours that the male students in this sample spent watching YouTube is 12 hours per week, with an estimated standard deviation of 2.5. The mean number of hours that the female students in this sample spent watching YouTube is 10 hours per week, with an estimated standard deviation of 3.5. To solve the leader's proposal, c) What type of hypothesis test should be adopted? Please state your null hypothesis and alternative hypothesis. d) Calculate the t-test statistic. Assume the signicance level is .05, what is the p-value? What statistical decision will you make based on the p-value. Researchers in Indiana University and Ohio State University are doing the same project in their institutes and are willing to share their data. Your group is interested in nding out whether the mean number of hours spent watching YouTube is different between the students in Penn State, Indiana, and Ohio State. e) What statistical test would you suggest? Please write out the null hypothesis and alternative hypothesis and explain their meanings in plain words. Q5. Please read the following two questions on a survey: Overall Satisfaction (0-100) 1. Overall, how satised were you in the past year with the electric services provided to you by FirstEnergy Solutions? Please list a number in between 0 and 100, where a higher number means you were more satised. Firm Size 6. Approximately how many full-time employees does you rm currently have? ________ Number of employees The following table is the SPSS output after running a correlation test with these two variables: Correlations Q5. Please read the following two questions on a survey: Overall Satisfaction (0-100). 1. Overall, how satisfied were you in the past year with the electric services provided to you by FirstEnergy Solutions? Please list a number in between 0 and 100, where a higher number means you were more satisfied. Firm Size 6. Approximately how many full-time employees does you firm currently have? Number of employees The following table is the SPSS output after running a correlation test with these two variables: Correlations Overall Firm size (# Satisfaction employees) Overall Satisfaction Pearson Correlation 1.000 .656 Sig. (2-tailed) 000 N 128.000 128 Firm size (# employees) Pearson Correlation -.656" 1.000 Sig. (2-tailed) 000 N 128 128.000 Please Answer the following TWO questions: a) What is the sample correlation coefficient (r)? b) Based on the table, can you test the hypothesis that there is no relation between firm size and overall satisfaction. Please formulate your hypotheses (HO and H1), make statistical decision (reject or not reject and why), and draw your managerial conclusions. Previous Next