Question

1a. The following statement demonstrates which type of statistics: “On average, students in my urban studies class are twenty-one years old.”

a.Inferential Statistics

b.Descriptive Statistics

c.Both of the above

d.None of the above

1b.) A researcher wants to study the number of job interviews of graduating seniors in the United States. What would be the key variable for the researcher?

a.Number of graduating seniors

b.Average GPA for the student body

c.How long it took the average senior to find a job

d.Number of job interviews each respondent had

1c.) Identify the sampling technique used (cluster, convenience, simple random, stratified, systematic). “Take a sample of five zip codes from the Cleveland metropolitan region and use every elementary school from each of the zip code regions. Determine the number of students enrolled in first grade in each of the schools selected.”

a.Simple

b.Systematic

c.Cluster

d.Stratified

e.convenience

1d.) Identify the sampling technique used (cluster, convenience, simple random, stratified, systematic). “Split Internet users into different age groups and then select a random sample from each age group to determine the amount of time they are online each month.”

a.Simple

b.Systematic

c.Cluster

d.Stratified

e.convenience

1e.) Identify the sampling technique used (cluster, convenience, simple random, stratified, systematic). “Ask five friends for their opinions about the student cafeteria.”

a.Simple

b.Systematic

c.Cluster

d.Stratified

e.convenience

Answer 1

1a. Inferential Statistics estimates the population parameter based on the sample data while descriptive statistics just describes a phenomenon based on data or calculations. The given statement is describes, on average, the ages of students in particular class, hence the statement demonstrates descriptive statistics. Thus option (b) is correct.

1b. Since the researcher wants to study the no. of job interviews of GRADUATING SENIORS in the United States, the key variable will be the 'no. of graduating seniors'. Thus, option (a) is correct.

1c. In cluster sampling, the population is divided into clusters and after selecting some clusters at random, EACH elementary unit from these selected clusters are taken as the sample. In this example, since every elemetary school from each of the 5 zip codes is taken as the sample, this is a case of cluster sampling. Thus, option (c) is correct.

1d. In stratified sampling, the population is first divided into homogeneous subgroups and then a random sample is taken from each subgroups. In this example, since internet users are first split into different age groups and then a random sample is taken from each sub group, this is a case of stratified sampling. Thus, option (d) is correct.

1e. In convenience sampling, the sample is chosen with no particular assignment of probability or no rule of probability instead, the sample is chosen according to the convenience of the investigator. In this example, five friends are casually asked for their opinions about the student cafeteria, this is a case of convenience sampling. Thus, option (e) is correct.