Matrix multiplication with @ operator in NumPy - Mini Project: Build & Apply

Matrix multiplication with @ operator

📖 Scenario: Imagine you work in a small company that analyzes sales data. You have two tables of numbers: one shows sales by product and month, and the other shows the price of each product. You want to find the total sales revenue for each month by multiplying these tables.

🎯 Goal: You will create two matrices using numpy, then multiply them using the @ operator to find total sales revenue per month.

📋 What You'll Learn

Create two numpy arrays with exact values

Use a variable to store the result of matrix multiplication

Use the @ operator for matrix multiplication

Print the resulting matrix

💡 Why This Matters

🌍 Real World

Matrix multiplication is used in many fields like sales analysis, computer graphics, and machine learning to combine data efficiently.

💼 Career

Knowing how to multiply matrices with numpy is a key skill for data scientists and analysts working with numerical data.

1

Create sales and price matrices

Import numpy as np. Create a numpy array called sales with these exact values: [[10, 20, 30], [5, 10, 25]]. Create another numpy array called prices with these exact values: [[2], [3], [4]].

NumPy

# Your code here

Need a hint?

Use np.array() to create matrices with the exact numbers given.

2

Create a variable for total revenue

Create a variable called total_revenue and set it to None as a placeholder.

NumPy

import numpy as np
sales = np.array([[10, 20, 30], [5, 10, 25]])
prices = np.array([[2], [3], [4]])
# Your code here

Need a hint?

Just create the variable total_revenue and assign None for now.

3

Multiply matrices using @ operator

Use the @ operator to multiply sales by prices. Store the result in the variable total_revenue.

NumPy

import numpy as np
sales = np.array([[10, 20, 30], [5, 10, 25]])
prices = np.array([[2], [3], [4]])
total_revenue = None
# Your code here

Need a hint?

Use total_revenue = sales @ prices to multiply the matrices.

4

Print the total revenue matrix

Print the variable total_revenue to display the result of the matrix multiplication.

NumPy

import numpy as np
sales = np.array([[10, 20, 30], [5, 10, 25]])
prices = np.array([[2], [3], [4]])
total_revenue = sales @ prices
# Your code here

Need a hint?

Use print(total_revenue) to show the final matrix.