help please

9. A study showed that the mean time spent per day browsing the video streaming service Netflix for something to watch was 19.3 minutes. Assume o = 8. A simple random sample of 100 visits taken this year has a sample mean of 21.5 minutes. At the 5% level of significance, can we conclude that the mean time browsing Netflix has increased? Use the classical approach for your hypothesis test. (6)