Apply logistic regression to categorize whether a county had high mortality rate due to contamination

1. Import the necessary packages to read in the data, plot, and create a logistic regression model

2. Read in the hanford.csv file in the data/ folder

3. Calculate the basic descriptive statistics on the data

4. Find a reasonable threshold to say exposure is high and recode the data

5. Create a logistic regression model

6. Predict whether the mortality rate (Cancer per 100,000 man years) will be high at an exposure level of 50