A subject is asked to pick the suit of a card that she does not see, picked at random from a standard deck of playing cards. If the subject has no extra-sensory powers (ESO) her guesses should be correct, on average, 1 in 4 times. However, if she has ESP then the proportion of correct guesses should be better than 1 in 4.
(a) If the subject gets the suit correct 120 times in 400 trials, test (at the 5% level of significance) the statistical evidence that the subject might have ESP.
(b) Calculate the p-value for the test statistic value in (a) and interpret it.