Customers who use automatic teller machines $($ATM$)$ can perform several transactions quickly and efficiently. A banking consultant has noted that the times to complete a transaction are normally distributed with a standard deviation of $4$ seconds. If $77\%$ of customers take over $31$ seconds to complete their transactions, what is the average time $($in seconds$)$ it takes customers to complete a transaction?

Answer rating: 100% (QA)

To find the average time it takes customers to complete a transaction we need to determine the m... View the full answer