Basic stats

Question 1

Descriptive statistics

Answer 1

Describing the data you have and presenting it in an easily understandable manner

Question 2

Inferential statistics

Answer 2

Using data from a sample to make predictions or estimations about a larger group

Question 3

Mean

Answer 3

• Measure of centre
• Average value of a dataset
• Use it when data is normally distributed and doesn’t contain outliers
• Calculated by summing up all the values in a dataset and dividing by the total number of values

Question 4

Median

Answer 4

• Measure of centre
• Middle value in a dataset
• More robust to outliers
• Use it when the data is skewed or contains outliers

Question 5

Mode

Answer 5

• Measure of centre
• Value that appears most frequently in a dataset

Question 6

Variance

Answer 6

• Measure of spread
• Measures the dispersion or spread of the values in a dataset from the mean

Question 7

Standard deviation

Answer 7

• Measure of spread
• Square root of the variance
• Provides a measure of the average deviation of each data point from the mean
• A higher standard deviation indicates greater variability in the data

Question 8

Range

Answer 8

• Measure of spread
• Difference between the maximum and minimum values in a dataset

Question 9

IQR: Interquartile Range

Answer 9

• Measure of spread
• Quantifies the spread of a dataset
• Range between the first quartile (Q1) and the third quartile (Q3) of a dataset

Question 10

Sampling and simulations

Answer 10

Selecting a subset of individuals or observations from a larger population for analysis

Question 11

Regression analysis

Answer 11

Allows us to find out and predict how changes in one variable are associated with changes in another

Question 12

Hypothesis testing

Answer 12

Used to determine whether there is enough evidence to support a claim about a population parameter

Question 13

Confidence interval

Answer 13

A range of values that is likely to contain the true value of a population parameter

Question 14

Probability

Answer 14

Measures the likelihood of an event occurring

Question 15

Correlation

Answer 15

Measures the strength and direction of the relationship between two variables.
It ranges from -1 to 1, where:
1 indicates a perfect positive correlation
-1 indicates a perfect negative correlation
0 indicates no correlation
Correlation does not imply causation

Question 16

Signal VS Noise

Answer 16

Signal: true underlying pattern or effect you’re interested in detecting and understanding
Noise: random, irrelevant variations or errors that can distort the signal/pattern

Question 17

Exploratory Data Analysis (EDA)

Answer 17

Aims to understand the characteristics and relationships of the data (mostly through visualisations) leading to potential insights

Question 18

Univariate analysis

Answer 18

Analysis of each variable’s distribution individually

Question 19

Bivariate analysis

Answer 19

Explores relationships between pairs of variables

Question 20

Multivariate analysis

Answer 20

Explores relationships between three or more variables

Question 21

Normal distribution

Answer 21

• A symmetric, bell-shaped probability distribution where data clusters around the mean, with fewer data points in the tails
• Used in statistical analysis due to their predictable properties