*20 POINTS PLEASE HELP ME!!!!!!!!*

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

25. Which word does NOT describe the set of points? (1,5) (2, 2) (3, -1) (4,-4) (5, -7) (6,-10) Decreasing Function Increasing L

egoroff_w [7]

Answer:

it would be decreasing

Step-by-step explanation:

because it is a linear increasing function

for 1 it is going up from 1-6

and 2 it is a function because there isn't any multiples of the x values/ inputs that go to one y value/ output.

7 0

2 years ago

What is the length of QR rounded to the nearest whole number?

Furkat [3]

The answer to this question is D. 14

5 0

3 years ago

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Solise is planting 24 bushes and 16 trees in equal rows. She wants all the rows to be exactly the same with no plants left over.

ZanzabumX [31]

━━━━━━━━━━━━━━━ ♡ ━━━━━━━━━━━━━━━

Since Solise want to plant both trees and bushes in the same number of rows, you need to find the common factor.

Since the question is asking what the greatest number of rows she can plant, you have to find the greatest common factor.

The greatest common factor of 24 and 16 is 8.

You can plant 24 bushes in 8 rows (meaning you can divide it by 8), and 16 trees in 8 rows (meaning you can divide it by 8). Since the greatest number you can divide them both by is 8, the GCF of 24 and 16 is 8.

So the greatest number of rows Solise can plant is 8 rows.

━━━━━━━━━━━━━━━ ♡ ━━━━━━━━━━━━━━━

5 0

3 years ago

The boiling point of water is 212 degrees Fahrenheit. Can this thermometer be used to record the temperature of a boiling pot of

Salsk061 [2.6K]

Yes because the thermometer reads temperatures higher than 2.12 degrees

4 0

3 years ago

Read 2 more answers