A cleaning service firm recently began to outsource some of its workload. In an effort to see what impact outsourcing had on customer satisfaction, it sent a series of surveys to a randomly selected sample of recent clients. The sample of 100 clients gave an average customer satisfaction rating of 4.5 with a standard deviation of 1. The firm wants to know if this result is meaningfully different from their benchmark score of 4.0.

1.Calculate the standard error for mean customer satisfaction and enter it in the blank provided.

2.Provide a 95% confidence interval.

There is a 95% chance that the average satisfaction rating is at least
........... and not more than ........

3.Does the confidence interval allow you to reject the null hypothesis? yes or no

4.Can the firm make a substantiated claim about a change in customer satisfaction? yes or no
.