In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster. Driving A student of the author conducted a survey on driving habits by randomly selecting three different classes and surveying all of the students as they left those classes.

A political scientist is interested in the effect of government type on economic development, She wants to use a sample of 30 countries evenly represented among the Americas, Europe, Asia, and Africa to conduct her analysis. What type of study should she use to ensure that countries are selected from each region of the world?   a. Observational - simple random sampling   b. Observational - cluster sampling   c. Observational - stratified sampling   d. Experimental

A vaccine to prevent a severe virus was given to children within the first year of life as part of a drug study. The study reported that of the 3456bchildren randomly assigned the​ vaccine, 58 got the virus. Of the 1606 children randomly assigned the​ placebo, 46 got the virus. a. Find the sample percentage of children who caught the virus in each group. Is the sample percentage lower for the vaccine​ group, as investigators​ hoped? b. Determine whether the vaccine is effective in reducing the chance of catching the​ virus, using a significance level of 0.01.The first few steps of the​ hypothesis-testing procedure are given. Complete the procedure.

A college alumni Organization sent a survey to all recent graduates to ask their annual income. 20% of the alumni responded, and their mean annual income was $40,000  with a standard deviation of $10,000. Explain why these data should not be used to construct a confidence interval for the mean annual income of all recent graduates.

The floor exercise is a commonly shared event between the Women’s and Men’s Artistic Gymnastics programs. Let’s compare the floor exercise scores of the female gymnasts and male gymnasts. To do this, we will consider the 2007, 2011, and 2015 results as sample data. Part B: Apparatus Finals Let’s now look at the floor exercise scores in the Female Apparatus Finals and in the Male Apparatus Finals. Female Apparatus Finals Score Male Apparatus Finals Score 15.25 14.35 14.85 14.05 14.2 14.05 13.95 13.95 13.65 13.85 13.3 13.4 12.7 12.8 0 11.55 14.6 13.6 14.45 13.4 14.2 13.35 13.55 13.1 13.25 13.1 12.85 13.05 11.8 12.7 11.25 12.4 15 13 14.9 12.7 14.45 12.65 14.3 12.65 13.7 12.6 13.55 12.25 13.45 12.15 13.15 12.05 i. Find the sample mean and sample standard deviation for the floor exercise scores in the Female Apparatus Finals. ii. Find the sample mean and sample standard deviation for the floor exercise scores in the Male Apparatus…

Identify the sampling techniques used in each scenario. e. surveying movie-goers as they exited the late movie, researchers determined that only young adults under the age of 22 see movies in the theater anymore.

The department head of a private secondary school in Marikina City surveyed randomly selected students from each grade level to know their readiness in limited face-to-face classes. a. Simple Random Sampling b. Systematic Sampling c. Stratified Sampling d. Cluster Sampling

To collect data about the number of students in your high school who have a part time job, which of the following methods is most likely to lead to a sample that is the most representative of the students in your school? Interview all the girls in the school. Ask the principal. Interview all the students in 9th grade. Assign each student in the school a number and randomly select students to be interviewed. Interview all the students who are on the sports teams in the school.

Sociologists argued that women on average earn less than men as women often choose to work less hours. They further suggest that the choice of hours worked may be driven by various factors such as age, childcare needs, occupation choice and flexibility. To investigate the relation between hours worked and income earned by Australian men and women, a researcher plans to survey a sample of individuals across the country. Briefly explain a) What type of survey method the researcher could use and why? b) What sampling method could the researcher use to select his/her sample and why? c) What are the two main variables the researcher should consider collecting data for the purpose of the above analysis and why? Identify the data type(s) for the variables. d) What kind of issues the researcher may face in this data collection?   Suppose a researcher has collected data from a sample of 65 individuals using the sampling method you have proposed in (b). For each individual, the hours worked per…

A study was conducted to determine how people get jobs. The table list date from 400 randomly selected subjects. The data are bases on results from the National centter for Career Strategies.  Job source of survey respondent FREQUENCIES HELP-WANTED ads 56 EXECUTIVE SEARCH FIRMS 44 NETWORKING 280 MASS MAILING 20 TOTAL    1. What percentage of the respondents got job by either help-wanted ads or mass mailing? 2. What percentage of the respondent got jobs from networking?