www.gb513rank.com
Question 1
A group of investors wants to develop a chain of fast-food
restaurants. In determining potential costs for each facility, they
must consider, among other expenses, the average monthly electric
bill. They decide to sample some fast-food restaurants currently
operating to estimate the monthly cost of electricity. They want to be
90% confident of their results and want the error of the interval
estimate to be no more than $100. They estimate that such bills
range from $600 to $2,500. How large a sample should they take?
Question 2
Suppose a study reports that the average price for a gallon of self-
serve regular unleaded gasoline is $3.16. You believe that thefigure
is higher in your area of the country. You decide to test this claim
for your part of the United States by randomly calling gasoline
stations. Your random survey of 25 stations produces the following
prices (all in $). Assume gasoline prices for a region are normally
distributed. Do the data you obtained provide enough evidence to
reject the claim? Use a 1% level of significance.
3.27 3.29 3.20 3.23 3.16 3.07 3.15 3.23 3.21 3.14
Question 3
3.16 3.20 3.37 3.19 3.20 3.24 3.27 3.09 3.35 3.14 3.05 3.35 3.14 3.07
3.10