# Code Challenges

### Notebook-based Python and Data Science Code Challenges with Solutions

Difficulty / 10

## Mean of a List

1 / 10

Write a function that calculates the mean (average) of a list of numbers.

## Vector Dot Product

1 / 10

Use Python (or NumPy if you really *have* to) to calculate the dot product of two vectors represented as Python Lists.

## Standard Deviation of a List

2 / 10

Write a function that calculates the *sample* Standard Deviation of a list of numbers.

## Random Matrix

2 / 10

Can you write a function that will generate a matrix (2D Python List or NumPy Array) of integers - with an indicated dimensionality? We'll tell you the number of rows and columns that the matrix should have, you do the rest.

## FizzBuzz

2.5 / 10

FizzBuzz is one of the best-known code challenges in the world. Solving it with vanilla Python is fine. But things get spicy when other Python packages get involved.

## Median of a List

3 / 10

Write a function that calculates the median of a list of numbers.

## Variance of a List

3 / 10

Write a function that calculates the *sample* variance of a list of numbers.

## Sample Covariance

3 / 10

Try your hand at calculating the sample covariance between two random variables (lists of integers).

## Correlation Coefficient

3 / 10

Write a function to calculate the sample correlation coefficient (r). This task will be very approachable if you have already completed the Standard Deviation and Covariance code challenges.

## Simple Linear Regression

4 / 10

Demonstrate that you can calculate the correct slope and intercept coefficient using a simple linear regression model in Python.