In Sunday's Indianapolis Star, there was an artcle talking about all the new grocery stroes opening in Indy. One of the reasons that Indianapolis is so competivtive is because of the amount we spend on groceries and our increased demand for healthy foods. According to the marketing reasearch frms study, the typical grocery shopper spends an average of $139.62 per week. 28 people and a standard deviation of $27.3
A-90% cofidence interval for the true amount spent
B-Another chain claims $140 a week is spend, can they make that claim? Why or why not?
C-Wants the average to be within $5 at the 90% level. What size of a sample would he have to collect to do the study?