The graph of the function f(x) = -(x + 3)(x - 1) is shown
below.
which statement about the function is true?
the function is positive for all real values of x where
x< -1.
the function is negative for all real values of x where
< -3 and where x > 1.
the function is positive for all real values of x where
> 0.
the function is negative for all real values of x where
x< -3 or x> -1.
-6
4
ht
-2
+
2
4
6
x

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?