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What is a correlation coefficient and how do I use it?

What is a correlation coefficient and how do I use it?

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A correlation coefficient is a statistical measure that quantifies the degree to which two variables are related or move together. In other words, it assesses the strength and direction of a linear relationship between two variables. The correlation coefficient is denoted by the symbol r. The value of the correlation coefficient r ranges from -1 to 1: r=1 indicates a perfect positive correlation, meaning that as one variable increases, the other variable also increases proportionally. r=−1 indicates a perfect negative…

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What is Linear Regression?

What is Linear Regression?

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What is Linear Regression? Linear regression is a statistical method used to model the relationship between a dependent variable and one or more independent variables by fitting a linear equation to the observed data. The simplest form of linear regression involves two variables, with one being the predictor variable (independent variable) and the other being the response variable (dependent variable). The goal is to find the best-fitting linear relationship that can be used to make predictions about the response variable…

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A Picture Is Worth A Thousand Words-Creating Effective Data Visualizations

A Picture Is Worth A Thousand Words-Creating Effective Data Visualizations

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 We have all seen rows upon rows of numbers at one time and realized how difficult it could be to make sense of large amounts of data and make decisions from them. Presenting data in large tables creates some organization but can still be overwhelming to examine and process. An effective, easy and impactful way to present large amounts of data is by creating pictures or visualizations of your data to help organize and summarize it, especially if it is…

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How do I determine the standard deviation?

How do I determine the standard deviation?

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The standard deviation is the commonly used measure of variability when working with numeric data. It indicates how much, on average, each score in a set varies from the mean value of that set. It is usually represented by “s” or SD and is indicated as a +/- value. This single value demonstrates how much variability or dispersion is among scores in a set. To calculate the value, we must compute the deviation of each score from the mean and…

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How do I determine the range?

How do I determine the range?

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The range, which is the simplest and least precise of the measures of variability, is determined by subtracting the lowest score in a set of data from the highest score. It provides a measure that considers the two most extreme scores in a set without accounting for any of the other scores between the extremes. The formula for the range is r = h – l, Where r = range, h = the highest score in the set, and l…

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What are the measures of variability and how do I use them?

What are the measures of variability and how do I use them?

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Measures of variability, such as the range, variance, and standard deviation, are types of descriptive statistics that complement the measures of central tendency in describing data sets. These measures of variability reflect how scores differ or are spread or dispersed from one another. A more precise definition is the distance or amount a score in a data set differs from the typical score in the set, usually the mean. The three most common forms of variability are the range, variance,…

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How do I decide which measure of central tendency to use?

How do I decide which measure of central tendency to use?

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A common struggle for novice statisticians is choosing a measure of central tendency that is most appropriate in a given situation. It depends on the type of data you have and some basic data distribution characteristics. If your data values are categories or descriptive words (e.g., political party, eye color, the country where you were born), the mode is your best option. Categorical data is information that fits into finite options in which only one option can be true at…

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What is the mode and how do I use it?

What is the mode and how do I use it?

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The mode is the central tendency measure that indicates the data point that occurs most frequently in a set of scores. It measures the frequency of occurrence of each unique value and denotes the score that has the highest frequency. The data points that the mode can describe can be numeric (e.g., height in cm or weight in pounds) or word-based (e.g., eye color, the city in which you live). The data points are organized somehow, and the frequency of…

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What is the median and how do I use it?

What is the median and how do I use it?

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The median is another measure of central tendency representing the “middle score” in a set. It’s the point in a score distribution in which 50% of the scores fall below it and 50% fall above it. The median is usually represented by Md. but can sometimes be represented by M. Computing the median is a two-step process: List all the scores in order, starting with the highest value and progressing to the lowest. For example: 100, 88, 76, 65, 40, 25,…

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What is the mean and how do I use it?

What is the mean and how do I use it?

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The mean is the most commonly used measure of central tendency and is considered a descriptive statistic. In practical terms, it is the sum of all the values in a data set divided by the number of values. It is a single value that can summarize the value of many of the scores in the data set. It represents the middle of the score distribution, hence the term “measure of central tendency.” A simple version of the formula would be:…

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