Discrete or Continuous?
1-2 page 10 number 9: (link to questions)
Of 50 letters sent, 3 letters arrived at the target address. Is the number of letters a discrete or continuous variable? Why? Since there are gaps between the number of letters (e.g. you cannot mail 1.7 letters), the number of letters is a discrete variable.

1-2 page 10 number 11: (link to questions)
The mean weight of pennies currently being minted is 2.5 grams. Is the number of grams discrete or continuous? Why? Since there are no gaps between the number of grams (e.g. pennies can weigh 2.42 grams or 2.43 grams or 2.425 grams), the number of grams (or weight) of pennies is a continuous variable.