Braceros Car Aircon claims that the average cost of car aircon installation and repairs is 11,000. A sample of 60 repairs has an average of 10,600. The standard deviation of the sample is 300. At , is...

Braceros Car Aircon claims that the average cost of car aircon installation and repairs is 11,000. A sample of 60 repairs has an average of 10,600. The standard deviation of the sample is 300. At , is there enough evidence to reject the company’s claim?