Reference no: EM132847468

In a study of whether physical handicaps affect perceptions of employment qualifications, researchers showed videotapes of an employer interviewing an applicant, but both men were actors following a set script. In the videotapes the "applicant" appeared with different handicaps (none, amputee, crutches, hearing, wheelchair). A group of seventy students were randomly assigned (14 per group) to watch a videotape and evaluate the applicant's qualifications on a 100-point scale. The study aimed to assess whether the data provide evidence that the mean qualification scores differ significantly among the various handicaps presented. a) Is this an observational study or an experiment? Explain. b) Identify the explanatory and the response variable. For each one, indicate whether it is numerical or categorical.

a) How many pairs of groups can be compared, with a total of five groups?

e) Explain what the letters in the "connecting letters" report reveal.

Example 11-2: Hot Dogs (cont.) Reconsider the following summary statistics from our analysis of hot dogs: Sample size Sample mean (calories) Sample SD (calories) Sample mean (sodium) Sample SD (sodium) Beef 20 156.85 22.64 401.15 102.43 Meat 17 158.71 25.24 418.53 93.87 Poultry 17 118.76 22.55 459.00 84.74 a) For which response variable did we conclude that the population means are not the same for all three types of hot dogs? b) How many pairwise comparisons are possible with three groups? c) Make a prediction for which types differ significantly from which other types, in terms of mean number of calories