Which equation when solved results in different values of x than the other 3

Find the missing variable for a parallelogram: a = latex: 28in^2 28 i n 2 h = b = 6.3 in (1in=2.54cm)

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?

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.