Hi Im working on the below problem and having a hard tim fig

Hi! Im working on the below problem and having a hard tim figuring out what to enter in my TI-84 to get the standard deviation. I have the mean of 1.75, Please help.

At Rachel’s 11th birthday party, eight girls were timed to see how long (in seconds) they could hold their breath in a relaxed position. After a two-minute rest, they timed themselves while jumping. The girls thought that the mean difference between their jumping and relaxed times would be zero. Test their hypothesis.

Solution