(iv) According to the linear regression model, the predicted percent- age body f
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Question
(iv) According to the linear regression model, the predicted percent- age body fat is 50.655%. when BMI = 42. Comment on the reliability of this prediction.
(v) A medical researcher is considering using BMI to obtain esti- mated values for percentage body fat in order to reduce costs in a study. To justify this approach, they require that the estimates be accurate to within ±5%. Based on the regression analysis, ex- plain whether this approach is feasible.Hint: Consider the residual standard deviation.
(ii) Find the estimate, se, of the residual standard deviation. /1 mark 5(c). Shown below is output from the linear rcgression model. Bummary (1m (BodyFat BNI, data-adipose,subset BMIExplanation / Answer
based on the model results we see that the p value for BMI is statisitcally signficant , as it is less than 0.05 . However at the same time we see that the R2 value is 0.539 , this means that model can only explain 53.9% variation in the data , which is almost close to 50%.
Hence the model is not reliable in making the correct estimates for the body fat% based on the BMI values
b)
we know that The residual standard deviation is used to describe the standard deviation of points formed around a linear function, and is an estimate of the accuracy of the dependent variable being measured. Residual standard deviation is also referred to as the standard deviation of points around a fitted line. Here the value is 5.51 . Which means the value is slightly outside the acceptable range of +-5% . Hence the approach is not feasible based on the given acceptance criteria
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