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22 votes
A bag contains 4 red marbles and 6 blue marbles. A marble is drawn and then replaced. This is done 50 times. Round all answers to the nearest hundredth (two decimal places). What is the probability that a red marble is drawn:

a. exactly 15 times:

b. at least 15 times:

c. at most 15 times:

d. less than 15 times:

e. between 17 and 25 times, inclusive:

User Kelo
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2 Answers

12 votes
12 votes

Final answer:

To find the probability of drawing a red marble exactly 15 times, you can use the binomial probability formula. The formula is P(X=k) = (nCk) * p^k * (1-p)^(n-k), where n is the total number of trials, k is the number of successes, and p is the probability of success on a single trial.

Step-by-step explanation:

To find the probability of drawing a red marble exactly 15 times, we can use the binomial probability formula. The formula is:

P(X=k) = (nCk) * p^k * (1-p)^(n-k)

Where:

  • P(X=k) is the probability of getting exactly k successes
  • n is the total number of trials
  • k is the number of successes we want
  • p is the probability of success on a single trial

In this case, n = 50, k = 15, and p = 4/10 (since there are 4 red marbles out of 10 marbles in total).

Using this formula, P(X=15) = (50C15) * (4/10)^15 * (6/10)^(50-15).

Similarly, you can calculate the probabilities for the other parts of the question.

User Viewsonic
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2.9k points
18 votes
18 votes

Answer: e

Step-by-step explanation:

4+6= 10 and then divide by 50 and add 25 so 0.2+25+25.02 so then subtract 4 so about 21 or 21.02

User Neerajkh
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3.4k points