The following are all 5 quiz scores of a student in a statistics course. Each quiz was graded on a 10-point scale. 8, 7, 8, 7, 5 Assuming that these scores constitute an entire population, find the standard deviation of the population. Round your answer to two decimal places. if you anwer i will give you 100 dolar

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?