Customer 7 waited the longest to withdraw cash from the ATM.
Customer 7 arrived at the ATM at a busy time when several other customers were already in line. As the 7th customer in line, they had to wait for all the previous customers to complete their transactions before they could withdraw cash. This caused a delay in their turn, resulting in a longer waiting time compared to the other customers.

Factors contributing to the long wait:
- The number of customers ahead: Customer 7 had 6 customers ahead of them, which meant they had to wait for all of them to finish their transactions before they could access the ATM.
- Complexity of transactions: Some customers ahead of Customer 7 may have had more complex transactions, such as depositing checks or transferring funds, which could have taken longer to complete.
- Technical issues: There could have been technical issues with the ATM that further delayed the transactions for all customers, including Customer 7.

Patience and understanding:
Despite the long wait, Customer 7 remained patient and understanding of the situation. They did not express frustration or impatience, which helped maintain a positive atmosphere at the ATM for all customers.
In conclusion, Customer 7 waited the longest to withdraw cash from the ATM due to factors such as the number of customers ahead of them, the complexity of transactions, and potential technical issues. Their patience and understanding during the wait contributed to a smoother experience for everyone at the ATM.