AP Statistics Unit 1:

Individual: People, places, or things described by the data set.

Categorical: Placing individuals into groups

Quantitative: Numerical variables that you count, measure.

Discrete Variable: A quantitable variable that can take on a countable number of values, often representing whole numbers such as the number of students in a classroom or the number of cars in a parking lot.

Continuous Variable: A quantitative variable that can take on an infinite number of values within a given range, often representing measurements such as height, weight, or temperature.



Symmetric Distributions: A type of distribution where the left and right sides of the distribution are mirror images of each other, with equal numbers of observations on either side of the center point.

Left-Skewed Distributions: A distribution that tails off to the left (Negative Skew)

Right-Skewed Distribution: A distribution that tails off to the right (Positive Skew)

Unimodel Distribution: A distribution that has one clear peak or mode, indicating the most frequent value in the dataset.

Bimodel: A distribution that has two clear peaks or modes, suggesting the presence of two distinct groups within the dataset.

Multimodal Distribution: A distribution that has multiple peaks or modes, indicating that there are several distinct groups within the dataset.



Describing Data:

C: Center

U: Unusual Features

S: Shape

S: Spread


Distance from the mean: (X-27)

  • Center: The measure of the central tendency of the data, often represented by the mean or median.

  • Variability: The degree to which data points differ from each other and from the mean, often assessed using range, variance, or standard deviation.

  • Shape: The overall appearance of the distribution of data, which can be described as symmetric, skewed, or uniform.


    Standard Deviation: A statistic that quantifies the amount of variation or dispersion of a set of values, indicating how much the individual data points deviate from the mean.

    Calculating Standard Deviation:

    To calculate the standard deviation, follow these steps:

    1. Find the mean of the data set.

    2. Subtract the mean from each data point and square the result.

    3. Calculate the average of these squared differences.

    4. Take the square root of that average to obtain the standard deviation.