Descriptive Statistics: FULL Tutorial - Mean, Median, Mode, Variance & SD (With Examples)

Wondering what descriptive statistics are for? Here's how they show you the shape of your data before you analyze it. 🎓 GET 1-ON-1 DATA ANALYSIS HELP: https://go.gradcoach.com/MDC1p 🧰 FREE RESEARCH TOOLKIT: https://go.gradcoach.com/Rb6Pg THE KEY QUESTIONS WE ANSWER IN THIS VIDEO What are descriptive statistics? A way to summarize and describe the basic but essential features of a quantitative data set, such as a set of survey responses. They give you a snapshot of what your data look like. The simplest ones are a count of participants, which is your sample size, the proportion of males and females, or the percentage who answered a question a particular way. What is the difference between descriptive and inferential statistics? Descriptive statistics describe and summarize the data itself. Inferential statistics use data from a sample to make predictions about a larger population. Put simply, descriptives help you understand your sample, while inferentials let you make broader claims about the population it came from. Why do descriptive statistics matter if they are so simple? Two reasons. They let you spot problems fast, such as suspicious outliers or missing responses, while you can still do something about them. And they decide what inferential tests you may use, because every test carries assumptions about the shape of your data. Run one on data that is not shaped for it and the result is meaningless. What are the mean, median and mode? The three common measures of central tendency, which describe the middle of a data set. The mean is the mathematical average. The median is the middlemost number once you order them from lowest to highest. The mode is the most frequently occurring number. In the video's example of 15 customer service ratings, the mean is 5.8, the median is 6 and the mode is 5. What is a normal distribution, and what does skewness tell me? Plot how often each response occurs and the bars often cluster toward the middle, forming a bell shape. That is a normal distribution, or bell curve. Data can also lean left or right instead, and skewness is the statistic that measures that lean. Pay attention to it, because the shape of your data limits which inferential tests you can run. What are range, variance and standard deviation? The three common measures of dispersion, which describe how spread out your data are. Range is the largest number minus the smallest. Variance is the average of the squared differences between each data point and the mean. Standard deviation is the square root of the variance, and it is easier to read because it comes back in the same units as your original data. How does dispersion change the way I read the mean? It decides how much weight the mean can carry. If the data cluster tightly around the mean, the mean represents the center well. If they are scattered, it becomes less meaningful and needs interpreting with caution. That is why you report standard deviation alongside the mean: a standard deviation of 2.18 around a mean of 5.8 tells the reader the data are fairly spread out. OVERVIEW 00:00 Introduction 00:22 What descriptive statistics are, with examples 01:48 Descriptive vs inferential statistics 02:45 Why descriptive statistics matter more than they look 03:53 The big seven descriptives 04:17 Mean, median and mode explained 04:50 A worked example: 15 customer service ratings 06:05 Frequency distributions and the bell curve 06:41 Skewness: which way your data leans 07:14 Measures of dispersion, and why they matter 08:15 The range explained 08:42 Variance explained 09:11 Standard deviation explained 09:43 A worked example of range and standard deviation 10:31 Comparing a more tightly grouped data set 11:47 Recap of the key takeaways FREE RESOURCES What Are Descriptive Statistics? - https://go.gradcoach.com/xiWSy What Are Inferential Statistics? - https://go.gradcoach.com/Nyfb7 Quantitative Data Analysis 101 - https://go.gradcoach.com/ryVxm How Do I Choose the Right Statistical Test? - https://go.gradcoach.com/FGUka Sampling Methods & Strategies 101 - https://go.gradcoach.com/ua1qt Statistics Cheat Sheet - https://go.gradcoach.com/f1fsm Sampling Methods 101 -    • Sampling Methods 101: Probability & Non-Pr...   PREMIUM RESOURCES Research Methodology 101 (Blueprint) - https://go.gradcoach.com/y53Wk OUR SOCIALS 🟢 Facebook -   / gradcoachofficial   🟢 Twitter -   / gradcoachdotcom   🟢 LinkedIn -   / grad-coach-intl   🟢 YouTube -    / gradcoach