For Exercises 4.14 and 4.15, see pages 180–181; for 4.16 to 4.20, see pages 183–184; for 4.21 to 4.23, see pages 185–186; for 4.24, see page 187; for 4.25 and 4.26, see page 189; and for 4.27 to 4.29, see page 190.

Question 4.15

4.15 Describing sample spaces.

In each of the following situations, describe a sample space for the random phenomenon. Explain why, theoretically, a list of all possible outcomes is not finite.

  1. You record the number of tosses of a die until you observe a six.
  2. You record the number of tweets per week that a randomly selected student makes.

4.15

(a) Theoretically, it is possible to never roll a 6 because, each time, there is a chance the die will not be a 6. (b) Theoretically, no matter how many tweets the student made, he or she could make 1 additional tweet, which makes the outcomes infinite.