2. To test psychic abilities, parapsychologists use a special deck of
cards that have five symbols that are simple and yet look fairly different
from each other. (For example, squiggly lines, circle, star, etc.)
The deck has 100 cards, and there are 20 of each symbol. To test
whether someone can read minds, a "target" randomly selects a card from
the deck, looks at the card, and concentrates on that symbol. In
another room, the possible psychic then indicates which symbol he or she
thinks the target has selected. The investigator records whether
the psychic was right or wrong. The card is returned to the deck,
shuffled, and everything begins again. Suppose that, in 150
tries, a possible psychic gets 32 right. Is this evidence of psychic
ability, or is it more easily explained by chance variation?
a) State the null and alternative hypotheses as
statements about a box model.
b) What is the value of the test statistic z?
c) What is the p-value?
d) What do you conclude?