question archive a) combine the Setosa and Versicolor into group “0” and label the Virginica to “1”
a) combine the Setosa and Versicolor into group “0” and label the Virginica to “1”
Subject:SociologyPrice: Bought3
a) combine the Setosa and Versicolor into group “0” and label the Virginica to “1”. Create a new variable called iris$Group with the 0 or 1 labels,
b) build a logistic regression model using any available data that will predict the observation being Virginica ( value of 1 in Group variable),
c) calculate the probability of a new plant being a Virginica for the following parameters:
Sepal.Width =5 Petal.Length =10 Petal.Width =7 Sepal.Length=9
4.Using the kyphosis dataset:
a) convert the kyphosis$Kyphosis variable to numeric, assign a 1 to present and a 0 to absent,
b) build a logistic regression using all other variables and estimate the probability of the observation having a “present” hyphosis. What can you say about the coefficients? Are the significant?
c) calculate the probability of kyphosis being “present” for the following observation: Age=50, Start=10, Number=5.
5. Using all the single variable regressions from Exercise 1, test if the variable pairs are homoscedastic or heteroscedastic. Plot your findings. Using the plot(x=my_x_variable, y=my_y_variable, type=”p”) function. Use my_data$variable_name to define x and y variables in the function.
