A researcher is interested in the effect of music on memory. She randomly divides the students into 3 groups: those who will listen to quiet music, those who will listen to loud music, and those who will not listen to music. After the music is played (or not), she given students a memory test. What is the treatment variable

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?