BANL 1100 review 2

What is the main purpose of descriptive statistics?

• To predict future outcomes

• To summarize data using measures like mean and median

• To clean datasets

• To identify relationships between variables

What is the purpose of a box plot in EDA?

• To compare categorical variables

• To visualize the distribution and detect outliers in continuous data

• To show relationships between two continuous variables

• To display time-series trends

Which R function is used to calculate the mean of a numeric vector?

• median()

• mean()

• sum()

• mode()

In probability, what does 'mutually exclusive' mean?

• Events that cannot occur at the same time

• Events that are dependent on each other

• Events that always occur together

• Events with equal probabilities

Which statistical test would you use to determine if there is a significant association between two categorical variables?

• t-test

• ANOVA

• Chi-square test

• z-test

What does 'data imputation' involve in data cleaning?

• Removing all rows with missing values

• Replacing missing values with estimated values like mean or median

• Adding random data points to fill gaps

• Ignoring missing values during analysis

Which R package is most commonly used for creating visualizations like scatter plots and bar charts?

• tidyr

• ggplot2

• dplyr

• readr

What does the Central Limit Theorem state?

• All samples are normally distributed regardless of size

• The sampling distribution of the sample mean approaches normality as sample size increases

• Small samples are always accurate representations of populations

• All samples have equal variance

In Tidyverse, which function is used to pivot data from wide format to long format?

• pivot_longer()

• gather()

• pivot_wider()

• spread()

What does 'scaling' mean in data preprocessing?

• Removing outliers from the dataset

• Standardizing variables to have a mean of 0 and standard deviation of 1

• Binning continuous variables into categories

• Handling missing values in the dataset