What type of number is 18.62

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Can someone me do math because i am having a breakdown rn because i don’t get it

Afamily went out to dinner and their bill was $113.if they want to leave a 19% tip, how much should they leave.