Microsoft claimed that the average amount of hours its employees work per week is 40. A sample of 30 employees yielded a mean of 44 hours with a standard deviation of 8 hours. Is there evidence to...

Microsoft claimed that the average amount of hours its employees work per week is 40. A sample of 30 employees yielded a mean of 44 hours with a standard deviation of 8 hours.

Is there evidence to support the hypothesis that the mean is different than 40 hours with confidence level 95% (or alpha of 5%)?