Unit 2.5 Review Part 2

Front

What is a Z-score?

Back

A Z-score indicates how many standard deviations an element is from the mean. It is calculated using the formula: Z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

How do you calculate the Z-score for a given value?

Back

To calculate the Z-score, subtract the mean from the value and then divide by the standard deviation: Z = (X - μ) / σ.

Front

What are quartiles in statistics?

Back

Quartiles are values that divide a dataset into four equal parts. Q1 is the first quartile (25th percentile), Q2 is the median (50th percentile), and Q3 is the third quartile (75th percentile).

Front

How do you find the first quartile (Q1)?

Back

To find Q1, arrange the data in ascending order and locate the median of the lower half of the dataset.

Front

What is the median in a dataset?

Back

The median is the middle value when the data is arranged in ascending order. If there is an even number of observations, the median is the average of the two middle numbers.

Front

What is a box-and-whisker plot?

Back

A box-and-whisker plot is a graphical representation of a dataset that shows the minimum, first quartile, median, third quartile, and maximum.

Front

How do you interpret a box-and-whisker plot?

Back

In a box-and-whisker plot, the box represents the interquartile range (IQR), while the lines (whiskers) extend to the minimum and maximum values. The line inside the box indicates the median.

Front

What does it mean if a Z-score is negative?

Back

A negative Z-score indicates that the value is below the mean of the dataset.

Front

What does it mean if a Z-score is positive?

Back

A positive Z-score indicates that the value is above the mean of the dataset.

Front

How do you determine the percentage of data below a certain value?

Back

To determine the percentage of data below a certain value, you can use the cumulative distribution function (CDF) or analyze the data distribution.