1 2 3 Which hypothesis-testing procedure would you use in the following situation? Your manager wants to know whether there is a significant difference between the average times required to complete a particular task for the three levels of technician experience (one year on job, two years on job, three years on job). ____ Which hypothesis-testing procedure would you use in the following situation? YumYum Candy Company sells a jelly bean mixture. The company claims that 30% of the jelly beans are cherry flavored, 60% are lemon, and 10% are peach. The jelly beans are sold in packages of 100. Suppose a randomlyselected package of jelly beans has 50 cherry, 45 lemon, and 5 peach jelly beans. Is this consistent with YumYum's claim? ____ Which hypothesis-testing procedure would you use in the following situation? An auto parts store has a customer satisfaction rating of 88 percent. Is this store's rating significantly different from the national average of 94 percent? ____ 4 Which hypothesis-testing procedure would you use in the following situation? A company is testing a new diet pill. They ask a group of 37 people to rate their hunger before taking the pill and after taking the pill. Then they examine the results to see if there was a significant improvement in hunger ratings. ____ 5 Which sampling method is used in the following example? A researcher needs to draw a sample of children from an elementary school. She first randomly selects five classes from the school. Then she measures all students in the selected classes. ____ 6 Which sampling method is used in the following example? A researcher is studying orthopedic surgeons but can only find five. She asks these surgeons if they know any more. They give her several further referrals, who in turn provide additional contacts. In this way, she is able to contact sufficient surgeons. ____ Multiple Choice ____ Which of the following is a true statement? A) Although a correctly designed experiment can strongly suggest a cause-and-effect relationship, the only way of firmly establishing such a relationship is through a complete census. A Simple random B Stratified C Judgment D Convenience E Cluster F Snowball G Ex post facto H Chi-square test I ANOVA J Stability K Regression L Extrapolation M Two-related-samples test N Two-independentsamples test O One-sample test P Intra-rater Q Systematic B) A controlled experiment is often conducted in order to establish a cause-and-effect relationship that was first suggested by an observational study. C) If correctly designed, an observational study can establish a cause-and-effect relationship just as effectively as a correctly designed experiment. D) A simple method for overcoming bias in observational studies is to increase the sample size. E) In an experiment, the control group consists of selfselected participants who choose not to receive a designated treatment. ____ Which descriptive statistic is usually considered most appropriate for describing nominal data? A) Mode. B) Variance. C) Mean. D) Range. E) Median. ____ An internet provider asks a consultant to contact 130 residential clients and measure their level of satisfaction with their internet service. The consultant obtains an alphabetized list of client names and starting with the letter A, uses a random number generator to pick five names from this group. The consultant uses the same selection method for each of the other 25 letters and combines the 5 26 = 130 names into a group of clients to be surveyed. Which of the following statements is true? A) The selection method makes use of chance. B) The selection method results in a single-stage cluster sample. C) Each client has an equal probability of being included in the survey. D) The selection method introduces bias through sampling error. E) For a sample this size, it is best to let the researcher hand pick a representative set of clients. 7-4-13