Descriptive Statistics 2

What are measures of dispersion used for?

• To measure the central tendency of data
  
  

• To describe how similar or different a set of scores are to each other

• To determine the probability of an event occurring
  
  

• To find relationships between two variable

Which of the following is NOT a measure of dispersion?

• Range

• Mean

• Standard Deviation

• Variance

How is the range of a dataset calculated?

• By summing all values in the dataset

• By finding the median of the dataset

• By subtracting the smallest value from the largest value
  
  

• By dividing the sum of all values by the number of observations

When is the Semi-Interquartile Range (SIR) most useful?

• When the data is normally distributed

• When the data is highly skewed

• When dealing with categorical data
  
  

• When there are no outliers

What does the standard deviation represent?

• The sum of all deviation scores

• The square of the variance
  
  

• The square root of the variance

• The sum of squared deviations

What is the formula for the coefficient of variation?

• (Mean / Standard Deviation) × 100

• (Standard Deviation / Mean) × 100

• (Variance / Mean) × 100

• (Range / Mean) × 100

What does correlation measure?

• The central tendency of a dataset

• The relationship between two variables

• The probability of an event occurring
  
  

• The dispersion of a dataset

What is the range of the Pearson correlation coefficient (r)?

• -2 to +2
  
  

• -1 to +1

• 0 to 1

• 0 to 100

What is the main difference between correlation and regression?

• Correlation establishes relationships, while regression predicts values

• Correlation predicts values, while regression establishes relationships

• Correlation is used only for categorical data, while regression is for numerical data

• Correlation and regression are the same

What does a high standard deviation indicate about a dataset?

• The data points are close to the mean

• The data points are spread out from the mean

• The data has no variation

• The dataset has a small range