The McMillians noticed that the amount of natural gas they use at their house each month is related to the average monthly temperature, as shown in this scatter plot. The slope of the line best fit -2.5 therms per degree. Which explains how the slope can be interpreted? (PLEASE HELP ME, i don’t understand it!)

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?