The cost of the computer is $115.00 and the tax charged is $8.05. what is the tax rate

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

2 years ago

Jillian’s school is selling tickets for a play. The tickets cost $10.50 for adults and $3.75 for students. The ticket sales for

nevsk [136]

Answer:168

Step-by-step explanation: First you do 82 times 3.75 which is 307.50. Then you do 2071.5 - 307.5 = 1764 Then you do 1764 divided by 10.50 which is 168

9 0

3 years ago

Read 2 more answers

The solution to the system is (6,2) Select all the equations that could be the other equation in the system. PLZ HELPPPPPP there

Dovator [93]

9514 1404 393

Answer:

A, C

Step-by-step explanation:

The attached graph shows which lines go through the given point. They are ...

y = 1/2x -1 . . . . 1st selection

y = -1/6x +3 . . . 3rd selection

__

The equations can be found algebraically by substituting the given point in the equation and seeing if the result is a true statement.

a) 2 = (1/2)(6) -1 = 3 -1 . . . true

b) 2 = -3(6) . . . . false

c) 2 = -1/6(6) +3 = -1 +3 . . . true

d) 2 = 2/3(6) -1 = 4 -1 . . . . false

e) 2 = 4(6) -2 = 24 -2 . . . . false

f) 2 = -3/2(6) +6 = -9 +6 . . . . false

6 0

2 years ago

At a carnival, food tickets cost $2 each and ride tickets cost $3 each. A total of $1,240 was collected at the carnival. The num

const2013 [10]

Answer:

B

Step-by-step explanation:

The given equations satisfy the given conditions. There are 2 equations and 2 unknowns, so a certain solution can be found.

This can be solved using substitution,

Substituting eqn 2 to eqn 1:

2(2y – 10) + 3y =1240

Simplifying,

y = 180

x = 350

5 0

3 years ago

Harper needs to buy some new leotards for gymnastics practice. At the sporting goods store, she finds 2 leotards on sale for $24

Nonamiya [84]

Answer:

34.99

Step-by-step explanation:

22.38 divided by 2= 11.19 24.80 + 11.19= 34.99

hope this helps you :) have a great day and stay safe!

3 0

3 years ago