Data Science Practice Test 8

1. Which of the following can be used to impute data sets based only on information in the training set?

process

all of the mentioned

preProcess

postProcess

2. Point out the wrong statement.

Predictors might have only a handful of unique values that occur with very low frequencies

In every situation, the data generating mechanism can create predictors that only have a single unique value

The function findLinearCombos uses the QR decomposition of a matrix to enumerate sets of linear combinations

All of the mentioned

3. Point out the wrong statement.

Adding squared terms makes it twice continuously differentiable at the knot points

Asymptotics are used for inference usually

None of the mentioned

Adding squared terms makes it continuously differentiable at the knot points

4. Which of the following function can be used to flag predictors for removal?

searchCorrelation

none of the mentioned

findCausation

findCorrelation

5. How many outcomes are possible with bernoulli trial?

None of the mentioned

6. The least squares estimate for the coefficient of a multivariate regression model is exactly regression through the origin with the linear relationships.

False

True

7. Which of the following is correct with respect to residuals?

Positive residuals are below the line, negative residuals are above

Positive residuals are above the line, negative residuals are below

Positive residuals and negative residuals are below the line

All of the mentioned

8. Point out the correct statement.

Caret includes several functions to pre-process the predictor data

Asymptotics are used for inference usually

The function dummyVars can be used to generate a complete set of dummy variables from one or more factors

All of the mentioned

9. Which of the following is the correct formula for total variation?

Total Variation = Residual Variation - Regression Variation

Total Variation = Residual Variation + Regression Variation

All of the mentioned

Total Variation = Residual Variation * Regression Variation

10. caret does not use the proxy package.

True

False