Stats Fundamentals
This type of data can be classified into categories but cannot be ordered (e.g., eye color).
What is nominal level data?
The value that appears most frequently in a dataset.
What is the mode?
A collection of one or more outcomes of an experiment.
What is an event?
The characteristic symmetrical shape of a normal probability distribution.
What is bell-shaped?
A statement about a population parameter that is assumed to be true until proven otherwise. It always contains an equality sign.
What is the null hypothesis (H0)?
This graphical display shows the relationship between two quantitative variables, where each point represents an observation.
What is a scatter plot?
A measure of central tendency that is highly affected by extreme values or outliers.
What is the mean?
The probability of an event and the probability of its complement must sum to this value.
What is 1?
For a normal distribution, approximately 68% of the data falls within one standard deviation, 95% within two, and 99.7% within three standard deviations of the mean, according to this rule.
What is the Empirical Rule?
The probability of rejecting the null hypothesis when it is actually true. This is often denoted by α.
What is a Type I error (or alpha level)?
A specific type of bar chart used to display the frequency distribution of a quantitative variable. The bars touch.
What is a histogram?
The positive square root of the variance, measuring the typical distance of data points from the mean.
What is the standard deviation?
The specific term for the result of a single trial of a probability experiment.
What is an outcome?
A standardized value that indicates how many standard deviations an observation is from the mean of a normal distribution.
What is a Z-score?
The probability of observing a test statistic as extreme as, or more extreme than, the one calculated from the sample data, assuming the null hypothesis is true.
What is the p-value?
The sum of the relative frequencies for all classes in a frequency distribution must equal this value.
What is 1.0 or 100%?
A measure of position that divides a dataset into four equal parts.
What are quartiles?
If events A and B have no outcomes in common, meaning they cannot occur simultaneously, they are described as this.
What are mutually exclusive events?
The mean of a standard normal distribution.
What is 0?
When the p-value is less than the significance level (α), we perform this action regarding the null hypothesis.
What is reject the null hypothesis?
This type of data can be ordered, but the difference between values is not meaningful (e.g., movie ratings like good, better, best).
What is ordinal level data?
The difference between the third quartile and the first quartile, representing the spread of the middle 50% of the data.
What is the interquartile range (IQR)?
If the occurrence of one event does not affect the probability of another event occurring, the two events are considered this.
What are independent events?
To find probabilities for any normal distribution, you first convert the raw scores (X values) into these standardized scores.
What are Z-scores?
The conclusion reached if the p-value is greater than the significance level (α).
What is "fail to reject the null hypothesis" (or "there is not enough evidence to reject the null hypothesis")?