Jason inherited a piece of land from his great-uncle. Owners in the area claim that there is a 45% chance that the land
has oil. Jason decides to test the land for oil. He buys a kit
that claims to have an 80% accuracy rate of indicating oil in
the soil. If the test predicts that there is no oil, what is the
probability after the test that the land has oil?
0.1698
• 0.2217
• 0.5532
0.7660

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?