The average spending at Neco's salad bar is $9.14 with a standard deviation of $2.96. The distribution follows Normal distribution. The management is interested in the middle 80% of the customers...

Extracted text: The average spending at Neco's salad bar is $9.14 with a standard deviation of $2.96. The distribution follows Normal distribution. The management is interested in the middle 80% of the customers (spending wise) as it believes that they represent the customer base. What will be the difference between the upper and lower spending cut-offs which define the middle 80% of the customers?