On her way out of the toy store, Janelle stops to get 2 gumballs from the giant gumball machine. Her favorite flavor is blue raspberry, but only about 30% of the gumballs in the machine are blue. How likely is it that both of the gumballs Janelle gets will be blue? Janelle simulates the situation by putting 3 blue marbles and 7 yellow marbles in a bag. She picks a marble, then returns it to the bag, 2 times. Each time a blue marble appears, it represents a blue gumball. Janelle records the results by writing "B" for a blue marble and "Y" for a yellow marble. Here are the results of 20 trials: YY, YB, YY, YY, BY, YB, YY, BB, BY, YY, YY, YB, YY, YY, BY, YY, BY, YY, BY, YY Based on Janelle's results, what is the probability that both of the gumballs will be blue?
Q. On her way out of the toy store, Janelle stops to get 2 gumballs from the giant gumball machine. Her favorite flavor is blue raspberry, but only about 30% of the gumballs in the machine are blue. How likely is it that both of the gumballs Janelle gets will be blue? Janelle simulates the situation by putting 3 blue marbles and 7 yellow marbles in a bag. She picks a marble, then returns it to the bag, 2 times. Each time a blue marble appears, it represents a blue gumball. Janelle records the results by writing "B" for a blue marble and "Y" for a yellow marble. Here are the results of 20 trials: YY, YB, YY, YY, BY, YB, YY, BB, BY, YY, YY, YB, YY, YY, BY, YY, BY, YY, BY, YY Based on Janelle's results, what is the probability that both of the gumballs will be blue?
Understand Problem: Understand the problem and the simulation setup.Janelle uses a bag with 3 blue marbles and 7 yellow marbles to simulate picking gumballs from the machine. She picks a marble, returns it, and repeats the process. This represents the probability of picking a blue gumball each time.
Calculate Probability: Calculate the probability of picking a blue marble in one trial. Probability of picking a blue marble = Number of blue marbles / Total number of marbles =103=0.3.
Calculate Two Trials Probability: Calculate the probability of picking two blue marbles in two trials (since she returns the marble each time, the probability remains the same for each pick).Probability of both picks being blue = Probability of first blue pick × Probability of second blue pick = 0.3×0.3=0.09.
Analyze Experimental Results: Analyze the experimental results from Janelle's 20 trials to find the frequency of "BB" outcomes.Count of "BB" outcomes = 1.Total trials = 20.Experimental probability = Count of "BB" outcomes / Total trials = 1/20=0.05.
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