Statistics Fundamentals GMLE Practice Questions (Page 6)

Questions 26–30

1. 26expert · hard

   A machine learning team is evaluating a new fraud detection model. The model has a higher recall but lower precision than the current model. The cost of a false negative is $100, and the cost of a false positive is $10. The team must decide which model to deploy. Which consideration is most important?

   • AThe model with higher precision is always better because it reduces false alarms.
   • BThe model with higher recall is always better because it catches more fraud.
   • CThe model with the higher F1 score is always the best choice.
   • DThe total expected cost, which depends on the false positive and false negative rates and their costs.
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2. 27foundation · easy

   A dataset has a distribution that is skewed to the right (positively skewed). Which statement about the relationship between the mean and median is generally true?

   • AThe mean is greater than the median.
   • BThe mean and median are equal.
   • CThe mean is less than the median.
   • DThe relationship cannot be determined from skewness alone.
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4. 28application · medium

   A fraud detection system flags transactions as fraudulent. Historically, 1% of transactions are fraudulent. The system's test is 95% sensitive (detects fraud) and 90% specific (correctly clears non-fraud). A transaction is flagged. What is the probability that it is actually fraudulent?

   • AApproximately 1%
   • BApproximately 95%
   • CApproximately 8.8%
   • DApproximately 50%
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5. 29expert · hard

   A data scientist finds a correlation of 0.9 between ice cream sales and drowning incidents. They conclude that ice cream sales cause drowning. Which of the following is the most likely explanation for this correlation?

   • AThe correlation is too high to be spurious.
   • BA confounding variable, such as hot weather, drives both ice cream sales and swimming activity.
   • CIce cream sales directly cause drowning.
   • DDrowning incidents cause ice cream sales.
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6. 30foundation · easy

   In simple linear regression, what does the slope coefficient represent?

   • AThe expected change in the dependent variable for a one-unit change in the independent variable
   • BThe correlation between the independent and dependent variables
   • CThe value of the dependent variable when the independent variable is zero
   • DThe proportion of variance explained by the model
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