Now in this situation, he took seven, he took a sample size of seven, and then the population of days, it says that they've been using the group messaging app for over a year, so they've been using it for over 365 days. So seven is for sure less than or equal to 10% of 365, which would be 36.5. So we meet this condition, which allows us to meet the independence condition. Now the last condition is often known as the normal condition, and this is to feel good that the sampling distribution of the sample means right over here is approximately normal. And this is going to be a little bit different than what we saw with significance tests when we dealt with proportions. There's a few ways to feel good that the sampling distribution of the sample means is normal. One is is if the underlying parent population normal.