Using the one sample to the population t test?

#1
Hi guys, I am a first year statistics students and I'm a bit shaky on the subject. Please help me with the question below. Thanks!

Question4

The owner of a gym wanted to know if weight loss can be improved by a new exercise she devised that can be performed any time during the day. Usually a new member would lose weight at the rate of 3 lbs. per week on her normal regimen. The next 9 people she worked with obtained weight loss as follows: 3.65, 3.25, 4.01, 3.97, 3.65, 3.65, 4.04, 4.15, and 2.55. She thinks her way is better. Work out if she’s right. Using the one sample to the population t test, determine if there is a different? Is it practical? (Show and label each step)