Question

1. - / 2 points

the following graphical display is similar to one that appeared in usa today.
the graphical display is about how many cups - o - joe do you drink? with information: about 72% of americans drink coffee. and for coffee drinkers, the percentages of different drinking amounts: 1 cup a day 27%, 2 or more cups a day 45%, 1 cup a week 13%, 2 cups a week 15%.
use the information in this display to answer the following questions. assume that the percentages in the graph are representative of adult americans.
(a) what is the probability that a randomly selected adult american drinks coffee?
%
(b) the display associates 45% with the category two or more cups of coffee a day. for the chance experiment that consists of selecting an adult american at random, is 0.45 the probability that the selected individual drinks two or more cups of coffee a day, or is it the conditional probability that the selected individual drinks two or more cups of coffee a day given that he or she drinks coffee? explain.
○ this is the probability that the selected individual drinks two or more cups of coffee a day, because that probability is less than 72%, which is the percent of americans that drink coffee.
○ this is the conditional probability that the selected individual drinks two or more cups of coffee a day given that the individual drinks coffee, as the percentages in the display add up to 100. but we know that only 72% of americans drink coffee, so the percentages must be proportions of coffee drinkers.

1. - / 2 points

Explanation:

Part (a)

Step1: Identify the relevant percentage

The problem states that about 72% of Americans drink coffee. This percentage directly gives the probability that a randomly selected adult American drinks coffee.

To determine if 0.45 is a probability or a conditional probability, we analyze the context. The total percentage of Americans who drink coffee is 72%. The percentages in the graph (45%, 27%, 13%, 15%) add up to 100% (45 + 27 + 13 + 15 = 100). This implies these percentages are relative to the group of coffee drinkers (since only 72% of Americans drink coffee). So, 0.45 is the conditional probability that a selected individual drinks two or more cups a day given they drink coffee (because it's a proportion within coffee drinkers). The second option explains this correctly: it's a conditional probability as the percentages sum to 100 (for coffee drinkers) and only 72% of Americans drink coffee, so they're proportions of coffee drinkers.

Answer:

72

Part (b)