CBE CBE Business Statistics and Data Analysis 1

Question 1

In regression analysis, the R-squared (R²) statistic measures:

Accepted Answer

The proportion of variance in the dependent variable explained by the independent variable(s)

Answer

R² ranges from 0 to 1 and indicates how well the regression model fits the data by showing the share of variance in the outcome explained by the predictors.

Question 2

A Type I error in hypothesis testing occurs when:

Accepted Answer

A true null hypothesis is incorrectly rejected

Answer

A Type I error (false positive) is the mistake of rejecting the null hypothesis when it is actually true, with its probability equal to the significance level α.

Question 3

Which measure of central tendency is most affected by extreme outliers in a dataset?

Accepted Answer

Mean

Answer

The mean is calculated using all values in the dataset, so extreme outliers pull it significantly away from the center of the distribution.

Question 4

In time series analysis, autocorrelation refers to:

Accepted Answer

The correlation of a variable with its own past values

Answer

Autocorrelation (serial correlation) measures the degree to which a time series is correlated with lagged versions of itself, violating OLS regression assumptions.

Question 5

The standard error of the mean (SEM) decreases as:

Accepted Answer

Sample size increases

Answer

SEM equals the population standard deviation divided by the square root of sample size, so larger samples produce more precise estimates of the population mean.

(CBE) Certified Business Economist Practice Test

(CBE) Certified Business Economist Practice Test

CBE CBE Business Statistics and Data Analysis 1