In a certain city, a fast food chain feels it is giving a bad reputation because it takes too long to serve the customer. Since the chain had four restaurants in this town, it is concerned with whether all restaurants have the same average servicing time. One of the owners of the fast food has decided to visit each of the store and monitor the service time for five randomly selected customers. At his four hour time visits he recoded the following service times in minutes.
RESTAURANTS
Restaurant 1
3, 4, 5.5, 3.5, and 4
Restaurant 2
3, 3.5, 4.5, 4 and 5.5
Restaurant 3
2, 3.5, 5, 6.5 and 6
Restaurant 4
3, 4, 5.5, 2.5 and 3
( a) use 1 percent significance level , do all the restaurants has the same mean service time?
( b) based on these results , should the owner make any policy recommendations to any of the restaurant managers?