Algebra 1 Statistics

Front

What is the interquartile range (IQR)?

Back

The interquartile range (IQR) is a measure of statistical dispersion, calculated as the difference between the third quartile (Q3) and the first quartile (Q1). It represents the range of the middle 50% of the data.

Front

How do you identify an outlier in a data set?

Back

An outlier is a data point that is significantly different from the other observations. It can be identified using the IQR method: any value that is less than Q1 - 1.5*IQR or greater than Q3 + 1.5*IQR is considered an outlier.

Front

What is the median of a data set?

Back

The median is the middle value of a data set when it is ordered from least to greatest. If there is an even number of observations, the median is the average of the two middle numbers.

Front

How do you calculate the mean of a data set?

Back

The mean is calculated by adding all the values in the data set and then dividing by the number of values.

Front

What is a quartile?

Back

A quartile is a type of quantile that divides a ranked data set into four equal parts. The first quartile (Q1) is the median of the lower half, the second quartile (Q2) is the median of the data set, and the third quartile (Q3) is the median of the upper half.

Front

What does it mean if a data set is skewed?

Back

A data set is skewed if it is not symmetrical and has a longer tail on one side. Right skewed (positive) means the tail is on the right, while left skewed (negative) means the tail is on the left.

Front

What is the range of a data set?

Back

The range is the difference between the highest and lowest values in a data set. It provides a measure of how spread out the values are.

Front

What is a box plot?

Back

A box plot is a graphical representation of a data set that shows the median, quartiles, and potential outliers. It provides a visual summary of the distribution.

Front

How do you find the first quartile (Q1)?

Back

To find Q1, order the data set from least to greatest and find the median of the lower half of the data.

Front

What is the third quartile (Q3)?

Back

Q3 is the median of the upper half of the data set, representing the 75th percentile.