Find the standard deviation of 12, 6, 7, 3, 15, 10, 18 and 5.

E-commerce is buying and selling online. Types: B2C (business to consumer – online shopping), B2B (business to business – wholesale trading), C2C (consumer to consumer – platforms like Jiji).

Advantages: convenience, wider selection, price comparison, 24/7 availability, lower overhead for sellers. Disadvantages: cannot examine goods physically, security concerns, delivery logistics.

E-commerce growing rapidly in Nigeria: Jumia, Konga, social media selling. Challenges include: internet access, payment systems, delivery infrastructure, trust issues. Mobile commerce (m-commerce) particularly important.