PLZ HELP WILL GIVE BRAINLIEST

Suppose that 50% of all young adults prefer McDonald's to Burger King when asked to state a preference. A group of 12 young adul

ddd [48]

Answer:

a) 0.194 = 19.4% probability that more than 7 preferred McDonald's

b) 0.787 = 78.7% probability that between 3 and 7 (inclusive) preferred McDonald's

c) 0.787 = 78.7% probability that between 3 and 7 (inclusive) preferred Burger King

Step-by-step explanation:

For each young adult, there are only two possible outcomes. Either they prefer McDonalds, or they prefer burger king. The probability of an adult prefering McDonalds is independent from other adults. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

50% of all young adults prefer McDonald's to Burger King when asked to state a preference.

This means that $p = 0.5$

12 young adults were randomly selected

This means that $n = 12$

(a) What is the probability that more than 7 preferred McDonald's?

$P(X > 7) = P(X = 8) + P(X = 9) + P(X = 10) + P(X = 11) + P(X = 12)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 8) = C_{12,8}.(0.5)^{8}.(0.5)^{4} = 0.121$

$P(X = 9) = C_{12,9}.(0.5)^{9}.(0.5)^{3} = 0.054$

$P(X = 10) = C_{12,10}.(0.5)^{10}.(0.5)^{2} = 0.016$

$P(X = 11) = C_{12,11}.(0.5)^{11}.(0.5)^{1} = 0.003$

$P(X = 12) = C_{12,12}.(0.5)^{12}.(0.5)^{0} = 0.000$

$P(X > 7) = P(X = 8) + P(X = 9) + P(X = 10) + P(X = 11) + P(X = 12) = 0.121 + 0.054 + 0.016 + 0.003 + 0.000 = 0.194$

0.194 = 19.4% probability that more than 7 preferred McDonald's

(b) What is the probability that between 3 and 7 (inclusive) preferred McDonald's?

$P(3 \leq X \leq 7) = P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 3) = C_{12,3}.(0.5)^{3}.(0.5)^{9} = 0.054$

$P(X = 4) = C_{12,4}.(0.5)^{4}.(0.5)^{8} = 0.121$

$P(X = 5) = C_{12,5}.(0.5)^{5}.(0.5)^{7} = 0.193$

$P(X = 6) = C_{12,6}.(0.5)^{6}.(0.5)^{6} = 0.226$

$P(X = 7) = C_{12,7}.(0.5)^{7}.(0.5)^{5} = 0.193$

$P(3 \leq X \leq 7) = P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) = 0.054 + 0.121 + 0.193 + 0.226 + 0.193 = 0.787$

0.787 = 78.7% probability that between 3 and 7 (inclusive) preferred McDonald's

(c) What is the probability that between 3 and 7 (inclusive) preferred Burger King?

Since $p = 1-p = 0.5$ , this is the same as b) above.

So

0.787 = 78.7% probability that between 3 and 7 (inclusive) preferred Burger King

7 0

3 years ago

Explain what is wrong with each of the following randomization procedures, and describe how you would do the randomization corre

zlopas [31]

Answer:

Kindly check explanation

Step-by-step explanation:

A.)

The problem with the here is that we might have introduced bias into our sample by failing to randomize the assignment of gender. By pacing the male gender in the treatment group and females into the control group, this might spring up a spurious association in our experiment as a result of a possible confounding variable, gender. Therefore, assignment of subject shouldn't be on the basis of gender.

2.)

Using a coin toss in placing subjects into groups will give a good random assignment, however, since only ten subjects are available and of which 5 will be placed into each group, there is no certainty that there will be equal number of heads and tails during the 10 flips. Alternatively, a random selection of the name of the 10 subjects could be chosen from a raffle.

3.)

Each batch of rat might be homogenous and hence will affect our experiment and definitely our conclusion. It would be best to assign rats from each batch to all treatment groups in other to obtain a good random design

8 0

3 years ago

Mike got in and elevator and whent down 3 floors. he meant to go to a lower level,so he stayed on the elevator and when down 3 m

Naily [24]

It is negative six because down three is -3 so 3+3 =6 but the numbers are negative so the answer is -6

7 0

3 years ago

HELP!! Can anyone answer this?

olya-2409 [2.1K]

I think that it is d

5 0

3 years ago

-1/3(n+15)=-2. what is n? please show work on paper and send it to me asap.

Anton [14]

Step-by-step explanation:

Use the distributive formula to solve for n:

-a(b + c) = -ab - ac

So, to solve this you would have to use the distributive property:

-1/3n - 5 = -2

Add 5 to both sides

-1/3n - 5 + 5 = -2 + 5

-1/3n = 3

Now, multiply -3 from both sides

-1/3 * -3 n = 3 * -3

Simplify

n = -9

Hope that helped!!

~A̷l̷i̷s̷h̷e̷a̷♡

4 0

3 years ago

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