Question

*Please Show Work* Researchers gave 40 index cards to a waitress at an Italian restaurant in...

*Please Show Work*

Researchers gave 40 index cards to a waitress at an Italian restaurant in New Jersey. Before delivering the bill to each customer, the waitress randomly selected a card and wrote on the bill the same message that was printed on the index card. Twenty of the cards had the message "The weather is supposed to be really good tomorrow. I hope you enjoy the day!" Another 20 cards contained the message "The weather is supposed to be not so good tomorrow. I hope you enjoy the day anyway!" After the customers left, the waitress recorded the amount of the tip (percent of bill) before taxes. Here are the tips for those receiving the good-weather message:

21.2   19.1   20.3   20.6   22.4   23.5   23.3   25.2   22.6   20.3

24.9   22.3   27.0   20.9   22.6   24.4   21.6   22.4   22.3   23.2

The tips for the 20 customers who received the bad-weather message are listed here:

18.0   19.3   19.4   19.1   18.4   19.5   18.7   16.3   16.8   14.3

17.0   14.1   17.8   20.2   20.7   19.2   18.0   23.3   18.7   19.8

(a) What degrees of freedom would you use in the conservative two-sample t procedures to compare the lack-of-control and in-control groups?
df =

What is the two-sample t test statistic? (Round your answer to three decimal places.)
t =

(b) Is there good evidence that the two different messages produce different percent tips? Report your conclusions. (Assume a 95% confidence level.)

There is not enough evidence to conclude that the mean tip percentage differs between the two types of forecasts presented to patrons. There is strong evidence that the mean tip percentage differs between the two types of forecasts presented to patrons.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
QUESTION 1: Researchers gave 20 index cards to a waitress at an Italian restaurant in New...
QUESTION 1: Researchers gave 20 index cards to a waitress at an Italian restaurant in New Jersey. Before delivering the bill to each customer, the waitress randomly selected a card and wrote on the bill the same message that was printed on the index card. 20 of the cards had the message "The weather is supposed to be really good tomorrow. I hope you enjoy the day!" Another 20 cards contained the message "The weather is supposed to be not...
Psychologists studied the size of the tip in a restaurant when a message indicating that the...
Psychologists studied the size of the tip in a restaurant when a message indicating that the next day's weather would be good was written on the bill. Data below gives info on the tips for 20 patrons, measured in percent of the total bill. Past experience with patrons of the restaurant indicate a stdev sigma = 2. Construct and Interpret a 95% confidence interval for the mean percentage tip for all patrons of this restaurant when they receive a message...
Problem #1 Confidence Interval for Means using the t and z Distribution.    Psychologists studied the percent...
Problem #1 Confidence Interval for Means using the t and z Distribution.    Psychologists studied the percent tip at a restaurant when a message indicating that the next day’s weather would be nice was written on the bill. Here are tips from a random sample of patrons who received such a bill, measured in percent of the total bill: 20.8     18.7     19.9     20.6     21.9     23.4     22.8     24.9     22.2     20.3   24.9     22.3     27.0     20.4     22.2     24.0     21.1     22.1     22.0     22.7 Open an...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT