An employer asks the survey question "How much money do you spend on gasoline per week to get to work?" of her employees that drive to work. Which best describes why she chose to only ask the employees that drive to work rather than all of her employees?

Shane can shovel the driveway in 4 hours, but if his sister it would take 2 hours. how long would it take taylor to shovel the driveway alone

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?

State one method by which you can recognize a perfect square trinomial.