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lyudmila [28]
2 years ago
15

You have a friend who claims to psychic. You don't believe this so you test your friend by flipping a coin 20 times and having h

im predict whether each flip is heads of tails. If you are right, and your friend is NOT psychic, then the probability of guessing correctly on each flip is .5. Your friend correctly guesses 15 out of the 20 flips. What is the probability of your friend correctly guessing 15 or more out of 20 flips if he is NOT really psychic? (Give your answer to at least 3 places past the decimal point)
Mathematics
1 answer:
Andre45 [30]2 years ago
8 0

Answer:

Given that your friend in not really psychic, he has a probability of P=1.5% of guessing right 15 out of 20 coin flips.

Step-by-step explanation:

We have a binomial distribution problem.

We have to calculate the probability of correctly guessing 15 out of 20 flips of a coin (probability of success for every trial: p=0.5).

We can calculate that with the binomial distribution formula:

P(x)=\frac{n!}{x!(n-x)!}p^x(1-p)^{n-x} \\\\P(15)=\frac{20!}{15!*5!}0.5^{15}*0.5^5\\\\P(15)=15504*0.5^{20}=15504* 0.00000095367 = 0.015

Then we can conclude that, given that your friend in not really psychic, it has only 1.5% of guessing right 15 out of 20 coin flips.

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It is clear that you will have more than X times Y if Y is less than 1 since dividing X by 1 is exactly X.

If you think of 10 and 1, you can divide 10 in exactly 10 portions of 1.
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4 0
2 years ago
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The gestation period of rhinos ​(487 ​days) is​ _____ percent longer than the gestation period of bears ​(220 ​days).
Talja [164]

Answer:

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Step-by-step explanation:

Given:

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To Find:

Percentage increase = ?

Solution:

The percentage increase =\frac{ \text{new value} - \text{final value} }{\text{final value}} \times 100

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2 years ago
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Answer:

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Step-by-step explanation:

Given that the probability distribution of X, where X is the number of job applications completed by a college senior through the school’s career center.

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4 0
2 years ago
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