Suppose a certain study reported that 27.7% of high school students smoke.
Random samples are selected from high school that has 632 students.
(i) If a random sample of 60 students is selected, what is the probability that
fewer than 19 of the students smoke?
(ii) If a random sample of 75 students is selected, what is the probability that
more than 17 of the students smoke?

Answer:

[tex]P(x=3)=0.2269[/tex]

Mean=2.1

Standard deviation=1.21

Step-by-step explanation:

We are given that

n=7

Probability of success, p=0.3

q=1-p=1-0.3=0.7

We have to find the probability of 3 success for the binomial experiment  and find the mean and standard deviation.

Binomial distribution formula

[tex]P(X=x)=nC_xp^{x}q^{n-x}[/tex]

Using the formula

[tex]P(x=3)=7C_3(0.3)^3(0.7)^{7-3}[/tex]

[tex]P(x=3)=7C_3(0.3)^3(0.7)^{4}[/tex]

[tex]P(x=3)=\frac{7!}{3!4!}(0.3)^3(0.7)^{4}[/tex]

[tex]P(x=3)=\frac{7\times 6\times 5\times 4!}{3\times 2\times 1\times 4!}(0.3)^{3}(0.7)^{4}[/tex]

Using the formula

[tex]nC_r=\frac{n!}{r!(n-r)!}[/tex]

[tex]P(x=3)=0.2269[/tex]

Now,

Mean, [tex]\mu=np=7\times 0.3=2.1[/tex]

Standard deviation, [tex]\sigma=\sqrt{np(1-p)}[/tex]

Standard deviation, [tex]\sigma=\sqrt{7\times 0.3\times 0.7}[/tex]

Standard deviation, [tex]\sigma=1.21[/tex]

Recall that for |x| < 1, we have

[tex]\displaystyle \frac1{1-x} = \sum_{n=0}^\infty x^n[/tex]

Differentiating both sides gives

[tex]\displaystyle \frac1{(1-x)^2} = \sum_{n=0}^\infty nx^{n-1} = \sum_{n=0}^\infty (n+1)x^n[/tex]

and multiplying both sides by 8 gives the series for f(x) :

[tex]f(x)=\displaystyle \frac8{(1-x)^2} = \boxed{8\sum_{n=0}^\infty (n+1)x^n}[/tex]

and this converges over the same interval, |x| < 1, so that the radius of convergence is 1.

9514 1404 393

Answer:

  (-3, 3)

Step-by-step explanation:

The blanks are trying to lead you through the process of finding the point of interest.

__

The horizontal distance from T to S is 9 . (or -9, if you prefer)

The ratio you're trying to divide the line into is the ratio that goes in this blank:

Multiply the horizontal distance by 2/3 . (9×2/3 = 6)

Move 6 units left from point T.

The vertical distance from T to S is 6 .

Multiply the vertical distance by 2/3 . (6×2/3 = 4)

Move 4 units up from point T.

__

Point T is (3, -1) so 6 left and 4 up is (3, -1) +(-6, 4) = (3-6, -1+4) = (-3, 3). The point that is 2/3 of the way from T to S is (-3, 3).

i think the answer is 2.24

include the notation and just do the work on the page

Answer: 0.86 and -2800 (choice A)

Explanation:

Think of the given equation as y = 0.86x - 2800

Then compare it to y = mx + b

We see that m = 0.86 is the slope and b = -2800 is the y intercept.

Answer:

Slope: 0.86 , Y-intercept:-2800

Step-by-step explanation:

Linear equations go by the form of y=mx + c

where m is the gradient(slope of the graph) and c is the y-intercept

Answer:

a. Set-builder form: {y | y is a natural number and 12 ≤ y ≤ 15}

Or

{y | y is a natural number and 11 < y < 16}

b. Rooster form: {3, 4, 5 ,6, ...}

Step-by-step explanation:

a. Rooster form: {12, 13, 14, 15}

All four numbers are natural numbers, therefore we would write this set of numbers in set builder form such that they will all have the same property. Thus:

Set-builder form: {y | y is a natural number and 12 ≤ y ≤ 15}

Or as

{y | y is a natural number and 11 < y < 16}

b. Set-builder form: {y | y is a natural number and y > 2}

Since natural numbers are positive integers, this tells us that all values of the set are not less than or equal to 2. Therefore, they are integers that range from 3 and above.

Thus:

Rooster form: {3, 4, 5 ,6, ...}

Answer:The correct answer is  They wanted to impede the sale of alcohol.

Step-by-step explanation:

They had beliefs that alcohol was against Christianity and that it ruins families and since it ruins families it should be prohibited. They eventually managed to win enough support and ban all alcohol which lasted for a few years before the prohibition ended.

Answer:

15

Step-by-step explanation:

By order of operations, multiplication and division are done first, then the addition and subtraction. Remember, multiplication and division have the same precedence, as does addition and subtraction.

21*6 = 126

126/7 = 18

18 + 12 = 30

30 - 15 = 15

Answer:

15

Step-by-step explanation:

21 × 6 ÷ 7 + 12 - 15​

= 126 ÷ 7 + 12 - 15

= 18 + 12 - 15

= 30 - 15

= 15

Answer:

Muhammad lives 8 km away from the school.

Hita lives 4 km away from the school.

Step-by-step explanation:

First of all, find a number that, when you double that number and add both numbers, you will get 12. That number is 4. So double 4 and get 8. Then add both to get 12.

Answer:

y+10=2

y=-8

Step-by-step explanation:

y=2-10

y=-8

Answer:

At the beginning, there were 2,678.26 grams of sugar in the container.

Step-by-step explanation:

Since Lisa used 880g of a container of sugar to bake a cake and 1/10 of the creaming sugar to make cookies, and she then had 3/7 of the container of sugar left, to determine how much sugar was in the container at first, the following calculation must be performed:

880 + 1 / 10X = 3 / 7X

880 + 0.1X = 0.4285X

880 = 0.4285X - 0.1X

880 = 0.3285X

880 / 0.3285 = X

2,678.26 = X

Therefore, at the beginning there were 2,678.26 grams of sugar in the container.

Answer:

Step-by-step explanation:

Answer:

3/8 x 5/8= 15/64

Step-by-step explanation:

Answer:

The correct answer is "76.98%".

Step-by-step explanation:

According to the question,

⇒ [tex]P(34000<x<46000) = P[\frac{34000-40000}{5000} <\frac{x- \mu}{\sigma} <\frac{46000-40000}{5000} ][/tex]

                                       [tex]=P(-1.2<z<1.2)[/tex]

                                       [tex]=P(z<1.2)-P(z<-1.2)[/tex]

                                       [tex]=0.8849-0.1151[/tex]

                                       [tex]=0.7698[/tex]

or,

                                       [tex]=76.98[/tex]%

Answer:

-2

-1

-2

Step-by-step explanation:

really ? this is a problem ? why ?

f(0) means the functional value for x = 0.

is x = 2 ? no.

so, automatically the other case applies, and f(0) = -2

f(2) means x=2

is x = 2 ? yes.

so that case applies, and f(2) = -1

f(5) means x=5

is x = 2 ? no.

so again, the case for x <> 2 applies, f(5) = -2

Answer:

Step-by-step explanation:

Are you trying to find a variable expression? the product of 86 means multiplication so 86*n or 86n. Other than that I dont understand the question.

Answer:

x is smaller than 5.6 and greater than 0

Answer:

Step-by-step explanation:

The sides of a 30-60-90 triangle are in the ratio 1:√3:2

The side opposite the 30° angle is (12√6)÷2 = 6/√6.

The side opposite the 60° angle is √3×6/√6 = 6/√2 =3√2.

The sides of a 45-45-90 triangle are in the ratio 1:1:√2

The hypotenuse is 3√2, so the side opposite the 45° angle is 3.

x = 3

Hi!

8 - 24 = -(24 - 8) = -16

Answer:

-16

Step-by-step explanation:

8-24=-16

This question is incomplete, the complete question is;

The distribution of scores on a recent test closely followed a Normal Distribution with a mean of 22 points and a standard deviation of 2 points. For this question, DO NOT apply the standard deviation rule.

What proportion of the students scored at least 23 points on this test, rounded to five decimal places?

Answer:

proportion of the students that scored at least 23 points on this test is 0.30850

Step-by-step explanation:

Given the data in the question;

mean μ = 22

standard deviation σ = 2

since test closely followed a Normal Distribution

let

Z = x-μ / σ      { standard normal random variable ]

Now, proportion of the students that scored at least 23 points on this test.

P( x ≥ 23 ) = P( (x-μ / σ) ≥  ( 23-22 / 2 )

= P( Z ≥ 1/2 )

= P( Z ≥ 0.5 )

= 1 - P( Z < 0.5 )

Now, from z table

{ we have P( Z < 0.5 ) = 0.6915 }

= 1 - P( Z < 0.5 ) = 1 - 0.6915 = 0.30850

P( x ≥ 23 ) = 0.30850

Therefore, proportion of the students that scored at least 23 points on this test is 0.30850

Answer: 9

Step-by-step explanation:

[tex] \frac{3}{5} \times 16.1 = 9.66[/tex]

Answer:

[tex]|F'H'| = 2 * |FH|[/tex]

Step-by-step explanation:

Given

[tex]E = (0,1)[/tex]             [tex]E' = (-1,2)[/tex]

[tex]F = (1,1)[/tex]             [tex]F' = (1,2)[/tex]

[tex]G = (2,0)[/tex]             [tex]G' =(3,0)[/tex]

[tex]H = (0,0)[/tex]            [tex]H' = (-1,0)[/tex]

[tex](x,y) = (1,0)[/tex] -- center

[tex]k = 2[/tex] --- scale factor

See comment for proper format of question

Required

Compare FH to F'H'

From the question, we understand that the scale of dilation from EFGH to E'F'G'H is 2;

Irrespective of the center of dilation, the distance between corresponding segment will maintain the scale of dilation.

i.e.

[tex]|F'H'| = k * |FH|[/tex]

[tex]|F'H'| = 2 * |FH|[/tex]

To prove this;

Calculate distance of segments FH and F'H' using:

[tex]d = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}[/tex]

Given that:

[tex]F = (1,1)[/tex]             [tex]F' = (1,2)[/tex]

[tex]H = (0,0)[/tex]            [tex]H' = (-1,0)[/tex]

We have:

[tex]FH = \sqrt{(1- 0)^2 + (1- 0)^2}[/tex]

[tex]FH = \sqrt{(1)^2 + (1)^2}[/tex]

[tex]FH = \sqrt{1 + 1}[/tex]

[tex]FH = \sqrt{2}[/tex]

Similarly;

[tex]F'H' = \sqrt{(1 --1)^2 + (2 -0)^2}[/tex]

[tex]F'H' = \sqrt{(2)^2 + (2)^2}[/tex]

Distribute

[tex]F'H' = \sqrt{(2)^2(1 +1)}[/tex]

[tex]F'H' = \sqrt{(2)^2*2}[/tex]

Split

[tex]F'H' = \sqrt{(2)^2} *\sqrt{2}[/tex]

[tex]F'H' = 2 *\sqrt{2}[/tex]

[tex]F'H' = 2\sqrt{2}[/tex]

Recall that:

[tex]|F'H'| = 2 * |FH|[/tex]

So, we have:

[tex]2\sqrt 2 = 2 * \sqrt 2[/tex]

[tex]2\sqrt 2 = 2\sqrt 2[/tex] --- true

Hence, the dilation relationship between FH and F'H' is::

[tex]|F'H'| = 2 * |FH|[/tex]

Answer:NOTT !!  A segment in the image has the same length as its corresponding segment in the pre-image.

Step-by-step explanation:

Answer:

The length of a side of a cubic die of volume equal to 343/4 is 4.41 inches.

Step-by-step explanation:

The volume of a cube is given by:

[tex] V = l^{3} [/tex]

Where:

l: is the length =?  

V: is the volume = 343/4 in³

By solving the above equation for "l" we have:

[tex] l = (V)^{1/3} = (343/4 in^{3})^{1/3} = 4.41 in [/tex]

Therefore, the length of a side of a cubic die of volume equal to 343/4 is 4.41 inches.

None of the options are correct for the given volume.

I hope it helps you!                                

Answer:

Step-by-step explanation:

g(5) = 2 > 0

:::::

g(x) = 0 for x = -2, 2, 4

:::::

g(x) < 0 for  -3 ≤ x < -2

Answer:

so you need a khan academy account?