Assuming that machine learning techniques are to be used in the following cases, identify whether the task required is supervised or unsupervised learning.Deciding whether to issue a loan to an applicant based on demographic and financial data $($with reference to a database of similar data on prior customers$).$

In an online bookstore, making recommendations to customers concerning additional items to buy based on the buying patterns in prior transactions.

Identifying a network data packet as dangerous $($virus$,$ hacker attack$)$ based on comparison to other packets whose threat status is known.

Identifying segments of similar customers