7:26 DOI LTE Take Quiz Exit O z-test, because the population standard deviation is unknown Question 10 3.33 pts You would like to see whether people living in Montclair sleep more than 8 hours on average or not. To that end, you collect a random sample of 50 people from a normally distributed population and your sample showed that the average time of sleep is 8. Also, you have known that the population standard deviation is 2. For hypothesis testing, which test statistics do you need to use? O neither z-test or t-test O either z-test or t-test O t-test O z-test Question 11 3.33 pts Assu tes 10