Problem 8E

(In some of the exercises that follow, we must make assumptions, such as normal distributions with equal variances.)

Different sizes of nails are packaged in “1-pound” boxes. Let Xi equal the weight of a box with nail size (4i)C, i = 1, 2, 3, 4, 5, where 4C, 8C, 12C, 16C, and 20C are the sizes of the sinkers from smallest to largest. Assume that the distribution of Xi is N(μi, σ2). To test the null hypothesis that the mean weights of “1-pound” boxes are all equal for different sizes of nails, we shall use random samples of size 7, weighing the nails to the nearest hundredth of a pound.

(a) Give a critical region for an α = 0.05 significance level.

(b) Construct an ANOVA table and state your conclusion, using the following data:

(c) For each set of data, construct box-and-whisker diagrams on the same figure and give an interpretation of your diagrams.

Psych 2300: Psychology Research Methods 6/15 & 6/17 Four Validities - Validity: appropriateness of a conclusion or decision Construct Validity Operationalization of a variable Applies to all claims Is this a reasonable way of quantifying what I want to understand Assessing creativity measure x : is x a reasonable way to measure creativity External Validity Generalizability o How was the sample gathered o Can I apply this elsewhere Can these results extend beyond my study Can I apply it to the population I am interested in Who can I apply these results to Representativeness How representative is your sample of the population of interest Specifically interested