In a random sample of 100 people the correlation

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2.In a random sample of 100 people, the correlation between amount of daily exercise and weight was found to be –.21. What wouldbe the likely effect on the absolute value of the correlation coefficient under the following circumstances? (Hint: would r be greateror smaller? Why?)
3.A researcher studying the relationship between maternal age and length of breastfeeding in a sample of 75 primiparas found a correlation of .19, which was not statistically significant at the .05 level. Utilize table 9.1 in book, use interpolation to find answersa.What was the estimated powerof the statistical test?
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b.Conversely, what was the risk that a Type II errorwas committed?
c.If .19 is a good estimation of the population correlation, what sample sizewould be needed in a replication study to achievepower = .80 at α= .05?
4.For this exercise, you will be using the SPSS dataset Polit2SetA. Begin by computing a correlation matrix for four variables usingAnalyze → Correlate → Bivariate. Move the following four variables into the slot for Variables: the woman’s age at first birth(age1bir), highest grade completed (higrade), number of hours worked per week, among women who were employed (workweek),and family income in the prior month (income). Check to make sure the following options are selected, as they usually are becausethey are the defaults: under Correlation Coefficients, Pearson; under Test of Significance, Two-Tailed, and Flag significantcorrelations. Click on the Options pushbutton, and click the option to obtain means and SDs for all variables. Also, select Excludecases pair-wise as the Missing Values option. Then click Continue and OK, and answer the following questions: a.What is the range of Ns for the four variables in this analysis?

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