descriptive statistics Flashcards
What are the three measures of central tendency?
The three measures of central tendency are the mean, median, and mode.
What is the formula for calculating the mean?
The mean is calculated by adding all the values in a dataset and dividing by the number of values.
What is the formula for calculating the median?
The median is the middle value when the data is arranged in ascending order. If there is an even number of values, the median is the average of the two middle values.
What is the formula for calculating the mode?
The mode is the value that occurs most frequently in a dataset.
What is the range?
The range is the difference between the highest and lowest values in a dataset.
What is the formula for calculating the standard deviation?
The standard deviation is calculated by taking the square root of the variance, which is the average of the squared differences from the mean.
What is a positive correlation?
A positive correlation occurs when two variables increase or decrease together, meaning that as one variable increases, the other also increases.
What is a negative correlation?
A negative correlation occurs when one variable increases while the other decreases, meaning they move in opposite directions.
What is a zero correlation?
A zero correlation means there is no relationship between two variables; changes in one variable do not affect the other.
What is the strength of using the mean?
The mean is useful because it considers all values in the dataset and provides an accurate measure of central tendency when the data is normally distributed.
What is the limitation of using the mean?
The mean can be skewed by extreme values (outliers), which can distort the true central value of the dataset.
What is the strength of using the median?
The median is useful when the data has outliers, as it is not affected by extreme values and provides a better measure of central tendency in skewed distributions.
What is the limitation of using the median?
The median does not take into account the actual values in the dataset, only their position, so it may not accurately reflect the overall data distribution.
What is the strength of using the mode?
The mode is simple to calculate and can be useful for categorical data, where other measures of central tendency may not be applicable.
What is the limitation of using the mode?
The mode may not be representative of the data, especially if there are multiple modes or if the data has no mode at all.
What is the strength of using the range?
The range provides a simple measure of how spread out the data is, showing the difference between the highest and lowest values.
What is the limitation of using the range?
The range is heavily influenced by outliers and may not accurately reflect the spread of most of the data, especially if there are extreme values.
What is the strength of using the standard deviation?
The standard deviation is a more accurate measure of dispersion than the range, as it considers how each value in the dataset deviates from the mean.
What is the limitation of using the standard deviation?
The standard deviation can be difficult to interpret without understanding the distribution of the data and may not be as meaningful in highly skewed distributions.
