Top Highlights

• If the p-value is less than or equal to the significance level, you reject the null hypothesis and your results are statistically significant.
• Descriptive statistics summarize data for a group that you choose.
• Descriptive statistics describe a sample. That’s pretty straightforward. You simply take a group that you’re interested in, record data about the group members, and then use summary statistics and graphs to present the group properties. With descriptive statistics, there is no uncertainty because you are describing only the people or items that you...
• In inferential statistics, we use sample statistics to estimate population parameters.
• You can think of the null as the default theory that requires sufficiently strong evidence in your sample to be able to reject it.