Biostatistics Exam 4 with correct answers

For the general form of multiple linear regression model, the fixed x1,
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x2,..., xi values, the y has a normal distribution with the what? - correct
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answer ✔Variance and the mean
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For the multiple linear regression model, each Bi can be interpreted as the
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true average change in y, EXCPET - correct answer ✔Bo
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For the multiple linear regression model, what happens when the xi
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increase by 1 unit? - correct answer ✔The values of all of the other
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predictors remain fixed
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For the multiple linear model, what are considered parameters? - correct
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answer ✔B0, B1, B3,... Bk
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For the multiple Linear Model, what are considered as constant? - correct
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answer ✔x1, x2, ..., x1
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For the sampling distribution of bi, bi has a normal distribution with the
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mean value of what? - correct answer ✔Bi
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For the sampling distribution of bi, the standard deviation of statistic bi,
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σi, involves what? - correct answer ✔σ^2
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, For the Multiple Regression, what is the variable selection? - correct
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answer ✔Number of observations (or sample size = n), should be at least
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twice the number of predictors in the model.
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For the multiple regression, what is the model selection? - correct answer
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✔- All-subsets vs. Stepwise (forward, backward)
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- R^2, adjusted R^, and Mallow's Cp
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For the Multiple regression, what is the multicollinearity? - correct answer
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✔It is a strong linear relationship between values of the predictor
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variables
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For the multiple regression, what does multicollinearity causes? - correct
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answer ✔It can cause instability of estimated coefficients as well as other
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problems
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For the multiple regression, what is diagnosis? - correct answer ✔It is
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computing the R2 values for regressions in which the dependent variables
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is taken to be one of the k x's and the predictors are the remaining (k-1)
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x's.
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For the multipe regression, what happends when the diagnosis R2 is large?
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- correct answer ✔If it close to 1, then it proves that the multicollinearity
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exists.
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What are the four common types of biological data? - correct answer ✔-
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Nominal (categorical)
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