Probability AP Statistics

In the wild, 400 randomly selected blooming azalea plants are observed and classified according to flower petal color (white, pink, or orange) and whether or not they have a fragrance. The table gives the results. If a single azalea plant is selected at random, which one of the following is the probability that it has pink flower petals or no fragrance?

• 0.04

• 0.635

• 0.595

• 0.555

In the wild, 400 randomly selected blooming azalea plants are observed and classified according to flower petal color (white, pink, or orange) and whether or not they have a fragrance. The table gives the results. If a single azalea plant is selected at random and found to be orange, what is the probability that it has no fragrance?

• 0.05

• 0.125

• 0.149

• 0.526

In a large city, 82% of residents own a cell phone. Suppose that we randomly select three city residents. What is the probability that at least one of the three residents does not own a cell phone? [The city is large enough so that we can assume independence].

• 0.994

• 0.449

• 0.006

• 0.551

A jar contains 10 red marbles and 15 blue marbles. If you randomly draw two marbles from the jar (without replacement), what is the probability that they are the same color?

• 0.5

• 0.15

• 0.52

• 0.48

A blood test for a certain disease has a false positive rate of 0.01 and a false negative rate of 0.05. (Recall that “false positive” means the test returns a positive result when the subject does not have the disease). Suppose that 2% of a certain population has the disease. If a random individual from this population tests positive, what is the probability that this person actually has the disease?

• 0.019

• 0.0098

• 0.0288

• 0.6597

A survey of high school students finds that 80% of them get news on current events from the internet, 25% of them get news from television, and 15% use both sources. Which of the following is an accurate Venn diagram of this information? [Let “I” = Get news from internet and “T” = Get news from Television.]

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Research on eating habits of families in a large city produced the following probabilities if a randomly selected household was asked “How often during the week do you have a vegetarian (meatless) main dish at dinnertime?” What is the probability that a randomly selected household never has a vegetarian main dish at dinnertime?

• 0.65

• 0.35

• 0

• 0.25