In a standard deck of cards, what is the theoretical probability of drawing a diamond?

In the final round of trivia competition, contestants were asked to name as many states that begin with the letter m as they could in 15 seconds. the bar graph shows the number of states the contestants were able to name. how many contestants participated in the final round of the competition? a) 6 b) 8 c) 14 d) 20

Julia chooses a card at random from her set of cards. what is the probability that the card is labeled cat or hamster?

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?