Question: Determining the range that the daily sales should fall 95% of the time. PLEASE HELP?
you have 500 average daily sales (X bar), a Standard deviation of 100 and a sample size of 25. The restaurant manager wants to know into what range the mean daily sales should fall 95% of the time.  Edit

Answer: x bar=500
using 68-95-97 rule the mean daily sales should fall 95% of the time is within 2 standard deviation of mean.

lower limit= x bar -2*sd=500-2*100=300
upper limit= x bar +2*sd=500+2*100=700
range is from 300 to 700.  Edit