# Regression your colleagues have collected some data

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Problem 6 Regression Your colleagues have collected some data on the relationship between the number of steps walked per day the BMI (body mass index: a summary of obesity). Your job is to analyze the data to see if there is a relationship between these two variables. Fill out the rest of this ANOVA table with numbers (cells to fill out are shaded) Source Sum of Squares Degrees of Freedom Mean Square F- Statistic P-value Model 36 1 (6.1) (6.5) (6.6) Error (6.3) (6.2) 6 Total (6.4) 41 6.7How many observations are there in the data set?
Which test statistic do we use as a general test for model significance in this case? (circle one) 6.9What is the critical value of the test statistic for MS Error22TMss221ln2MEssSSMSSE
6.10Can you reject the null hypothesis that there is no relationship between steps walked and BMI?
6.12How many degrees of freedom would the t-statistic have for this hypothesis test? MS ModelMS Error22TMss221ln2MEssSSMSSE
Practice Final 11 6.13What is the critical value for this t-test?
What is the p-value for this test statistic?
Do you get the same results from the t-test and the F-test?
6.16Why?
Practice Final 12 Problem 7 Cross tabulated count data A recent poll surveyed a simple random sample of 100 voters in Washington. Respondents were classified by age group and voting behavior. Use the following results to test the hypothesis that age is independent of voting behavior. OBSERVED Voted Did not vote Total 18 to 28 25 75 29 to 45 50 50 >45 75 25 Total 150 150 7.1 What is the general formula for the expected value of the cell counts under the null hypothesis that voting status is independent of age? Work out the expected values in this table under the null hypothesis that age is independent of voting preference. Show both the formula with plug in values, and solve for the answer. (7.2-7.7) EXPECTED Voted Did not vote Total 18 to 28 7.2 7.3 100 29 to 45 7.4 7.5 100 >45 7.6 7.7 100 Total 150 150 7.8 What is the general formula for the contribution of each cell to the Chi-squared statistic? 100 100 100 300 300
Practice Final 13 Work out the squared standardized residuals (zij2) in this table (7.9-7.14) zij2Voted Did not vote 18 to 28 7.9 7.10 29 to 45 7.11 7.12 >45 7.13 7.14 7.15What is the value of the Chi-square statistic for this test?
How many degrees of freedom does the Chi-square statistic for this test have? Show the formula with plug in values and the result 7.17What is the α=0.05 critical value of the Chisquared distribution for this test? -
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