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  3. HarvardX Data Science Module 4 - Inference and Modeling

Exercise

Exercise 6 - Predicting the Winner

Even if a forecaster's confidence interval is incorrect, the overall predictions will do better if they correctly called the right winner.

Add two columns to the cis table by computing, for each poll, the difference between the predicted spread and the actual spread, and define a column hit that is true if the signs are the same.

Instructions

100 XP
  • Use the mutate function to add two new variables to the cis object: error and hit.
  • For the error variable, subtract the actual spread from the spread.
  • For the hit variable, return "TRUE" if the poll predicted the actual winner. Use the sign function to check if their signs match - learn more with ?sign.
  • Save the new table as an object called errors.
  • Use the tail function to examine the last 6 rows of errors.