1. ## 99% Confident Level

I have gotten some basics from this question, but cannot think of the formula to match it. Too much information and I am lost.. PLEASE HELP!!!!

At the time she was hired as a server at the Grumney Family restaurant, Beth Brigden was told, “You can average more than $20 a day in tips.” Over the first 35 days she was employed at the restaurant, the mean daily amount of her tips was$24,85, with a standard deviation of $3.24. Can Ms. Brigden be 99% confident that she is earning an average of more than$20 per day in tips?

Mean: $24.85 Standard Deviation:$3.24

2. I would do a one sided hypothesis test where $H_0:\mu=20$ vs. $H_a:\mu >20$.
If you want to do a CI instead, it should be a one-sided CI.
This is a simple t-test with n-1=34 degrees of freedom.
The test stat is ${\bar X-20\over s/\sqrt{35}}$