13 points awarded
line segment ab has endpoints a(2, 9) and b(5, 8) . a dilation, centered at the origin, is applied to ab . the image has endpoints a ′ ( 4/3 , 6) and b ′ ( 10/3 , 16/3 ) .
what is the scale factor of this dilation?
a. 2
b. 3/2
c. 3
d. 2/3

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?