chapter1_What-is-statistics

What is statistics?

The field of statistics is the practice and study of collecting and analyzing data.

What is a summary statistic?

A summary statistic is a fact about or summary of some data.

What can statistics analyze regarding product purchases?

Statistics can analyze how likely someone is to purchase a product, and whether different payment systems affect purchasing likelihood.

What are descriptive statistics?

Descriptive statistics describe and summarize data.

What are inferential statistics?

Inferential statistics use a sample of data to make inferences about a larger population.

What types of data are there?

There are numeric (quantitative) data, which can be continuous or discrete, and categorical (qualitative) data, which can be nominal or ordinal.

How can categorical data be represented?

Categorical data can be represented as numbers, with nominal data as unordered and ordinal data as ordered.

Why does data type matter in statistics?

Data type informs the methods of analysis, including how to calculate summary statistics and create plots.

What is the mean?

The mean is the average of a set of values.

What is the median?

The median is the middle value of a dataset when sorted.

What is the mode?

The mode is the most frequent value in a dataset.

What is variance?

Variance measures the average distance from each data point to the data's mean.

What does standard deviation measure?

Standard deviation measures the amount of variation or dispersion of a set of values.

What is the interquartile range (IQR)?

The IQR is the height of the box in a boxplot, calculated as Q3 - Q1.

How do we identify outliers in data?

A data point is an outlier if it is less than Q1 - 1.5 × IQR or greater than Q3 + 1.5 × IQR.

What is the purpose of boxplots?

Boxplots are used to visually represent the distribution of a dataset and highlight its quartiles.

What is the purpose of histograms in statistics?

Histograms display the distribution of data values across intervals.

What does a left-skewed distribution indicate?

A left-skewed distribution indicates that the mean is less than the median.

What is a typical value in a dataset?

The typical value refers to the measure of center such as mean, median, or mode.

What statistical function would you use to calculate the mean in Python?

You would use np.mean() to calculate the mean.

What built-in Python function would you use to find the median?

You would use np.median() to find the median.

What is the recommended function in Python for calculating variance?

You can use np.var() to calculate variance, setting ddof=1 for sample variance.

How do you calculate the mean absolute deviation?

Mean absolute deviation is calculated as the average of the absolute distances from the mean.

What does a histogram show?

It shows the distribution of numerical data by depicting the frequency of data points in intervals.