IB Statistics Review

Front

What is the definition of median in statistics?

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 find the median of a data set?

Back

To find the median, first arrange the data in ascending order. If the number of observations is odd, the median is the middle number. If even, it is the average of the two middle numbers.

Front

What does it mean if a distribution is negatively skewed?

Back

A negatively skewed distribution has a longer tail on the left side, indicating that most data points are concentrated on the right.

Front

What is the definition of a normal distribution?

Back

A normal distribution is a symmetric, bell-shaped distribution where most of the observations cluster around the central peak and probabilities for values further away from the mean taper off equally in both directions.

Front

What is the 50th percentile in a data set?

Back

The 50th percentile is the median, which divides the data set into two equal halves.

Front

How do you interpret a box plot?

Back

A box plot displays the distribution of data based on a five-number summary: minimum, first quartile (Q1), median (Q2), third quartile (Q3), and maximum.

Front

What is the purpose of calculating the interquartile range (IQR)?

Back

The interquartile range (IQR) measures the spread of the middle 50% of a data set and is used to identify outliers.

Front

What is an outlier in a data set?

Back

An outlier is a data point that differs significantly from other observations, often due to variability in the measurement or it being a result of experimental error.

Front

How do you calculate the mean of a data set?

Back

To calculate the mean, sum all the values in the data set and divide by the number of values.

Front

What is the definition of standard deviation?

Back

Standard deviation is a measure of the amount of variation or dispersion in a set of values.