Sheryl's mean average on eight exams is 83.750. find the sum of her scores.
a. 770

b. 670

c. 693

d. 686

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?

Which two undefined geometric terms always describe figures with no beginning or end?

y=2x−1 5x−4y=1 is (1,1)(1,1) a solution of the system?