Question

what reason does the video provide for why americans have increasingly lighter wallets?
they are carrying fewer credit cards.
they have less expendable income.
they are choosing to carry less cash.
new bills are lighter than they used to be.
a random variable is a variable with a numeric value that varies for different members of the population of interest. a discrete random variable takes on a countable number of values, such as the number of children a person has. often discrete variables are counts, such that its possible to have a very large number of different values (e.g., from zero to infinity), but there are no possible values between two adjacent values. that is, it is possible to have 2 children or 3 children, but not any values in between 2 and 3.
a continuous random variable, such a persons height, can theoretically take on an infinite number of values. in particular, between any two values, there exists another. that is, you can be 73 cm, or 74 cm, or 73.4 cm. even though the value may be recorded rounded to the nearest centimeter, any value between 73 and 74 is theoretically possible.
what type of random variable is the weight of a persons wallet?
discrete
continuous
what type of random variable is the number of bills in a persons wallet?
continuous
discrete
part ii - discussion question
the video discusses the results of a survey of consumers. think about the questions they could ask these consumers and how their answers might be coded as variables. suppose you randomly selected one of these consumers from the study and defined the random variable x to be that persons value for one of the questions asked in the survey.
describe some possible random variables (other than the ones mentioned previously) and discuss whether they are continuous random variables or discrete random variables.

Explanation:

1. For the first question, based on common - sense and trends in modern payment methods, Americans are choosing to carry less cash, which makes their wallets lighter.
2. The weight of a person's wallet can take on any value within a range (e.g., 100.5 grams, 100.55 grams), so it is a continuous random variable.
3. The number of bills in a person's wallet is a count (e.g., 0 bills, 1 bill, 2 bills), so it is a discrete random variable. For the discussion part, possible random variables could be the number of credit - cards in the wallet (discrete, as it's a count) or the total value of the items in the wallet (continuous if considering cents and fractional values).

Answer:

1. They are choosing to carry less cash.
2. continuous
3. discrete
4. Possible random variables: Number of credit - cards in the wallet (discrete); Total value of items in the wallet (continuous).