data analysis with r coursera week 6 quiz answers
Final Exam
1. Which of the following is NOT a task facilitated by R?
- Model evaluation
- Data cleaning
- Model development
- Data generation
2. To combine functions, use the _____________________.
- slash
- two commas
- pipe operator
- parentheses
3. Which of the following is NOT true?
- Data formating ensures that data is consistent and easily understandable.
- Fully coherent data is consistent and can be reliably combined for analysis.
- In a data set, data is usually collected from a single source and stored in a single format.
- In statistics, coherence is an indication of the quality of the information in a single data set.
4. Which of the following situations does NOT call for data normalization?
- When the scale of a feature causes it to have a disproportional impact on results
- When there are outliers that might skew the results
- When you want to compare numerical and character values
- When different data set features are in very different ranges
5. Which of the following is NOT true of a scatter plot?
- It shows the relationship between two variables.
- It cannot suggest a liner relationship between two variables.
- Each observation is represented as a point.
- The predictor/independent variables are on the x-axis.
6. What does a P-score measure?
- If it is large, it indicate a strong correlation between variable categories and the target variable.
- It indicates whether the ANOVA test result is statistically significant.
- It indicates the validity of data within a data set.
- It is the ratio of various between group means over the variance within each of the sample group means.
7. A positive correlation is one in which _____________.
- both variables move in opposite directions
- both variables move in the same direction
- only one variable moves
- a causative relationship is shown
8. Which of the following is NOT true about a model?
- The amount of data you have should have no effect on the accuracy of the model.
- A model helps predict a value given one or more other values.
- Models work by relating one or more independent variables to dependent variables.
- Different types of models may be more accurate in different situations.
9. Which of the following is NOT a method for evaluating a regression model?
- Root mean squared error (RMSE)
- Root absolute error (RAE)
- Mean squared error (MSE)
- Mean absolute error (MAE)
10. A training set is ________.
- a small portion of the data used to evaluate the performance of a model
- a large portion of a data set that is used to build a sound model
- multiple data sets that have been run on the model
- a selected porion of the data set that is known to function well within the model
