SYM506 problems

12.43 In Problem 12.5 on page 441, you used the summated
rating of a restaurant to predict the cost of a meal. The data
are stored in RESTAURANTS ATTACHMENT . Using the results of that problem,
b1=1.2409 and Sb1=0.1421
a. At the 0.05 level of significance, is there evidence of a
linear relationship between the summated rating of a
restaurant and the cost of a meal?
b. Construct a 95% confidence interval estimate of the
population slope, b1.
12.17 In Problem 12.5 on page 441, you used the summated
rating to predict the cost of a restaurant meal (stored
in )RESTAURANTS ATTACHMENTS. For those data, SSR= 6,951.3963 and SST=15,890.11
a. Determine the coefficient of determination, and interpret
its meaning.
b. Determine the standard error of the estimate.
c. How useful do you think this regression model is for predicting
audited sales?
10.61 The per-store daily customer count (i.e., the mean number
of customers in a store in one day) for a nationwide convenience
store chain that operates nearly 10,000 stores has been
steady, at 900, for some time. To increase the customer count,
the chain is considering cutting prices for coffee beverages. The
question to be determined is how much to cut prices to increase
the daily customer count without reducing the gross margin on coffee sales too much. You decide to carry out
an experiment in a sample of 24 stores where customer counts have been running
almost exactly at the national average of 900. In 6 of the stores, the price of a small coffee will now be $0.59,
in 6 stores the price of a small coffee will now be $0.69, in 6 stores, the
price of a small coffee will now be $0.79, and in 6 stores, the price of a small coffee will now be $0.89. After
four weeks of selling the coffee at the new price, the daily customer count in
the stores was recorded and stored in COFFEE .
a. At the 0.05 level of significance, is there evidence of a
difference in the daily customer count based on the price
of a small coffee?