What are the zeros of the quadratic function represented by this graph?
У
A
6
2
X
-6
- 2
6
2-
-6-
A.
1 and 3
OB.
-3 and -1
C.
-3 and 1
D. -1 and 3

Answer:

(A) A 95% confidence for the population mean is [$332.16, $447.84] .

(B) If the confidence level in part (a) changed from 95% to 99%, then the margin of error for the confidence interval would increase.

(C) If the sample size in part (a) changed from 19 to 22, then the margin of error for the confidence interval would decrease.

(D) A 99% confidence interval for the proportion of students who purchase used textbooks is [0.363, 0.477]  .

Step-by-step explanation:

We are given that 19 students are randomly selected the sample mean was $390 and the standard deviation was $120.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

                             P.Q.  =  [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex]  ~ [tex]t_n_-_1[/tex]

where, [tex]\bar X[/tex] = sample mean = $390

            s = sample standard deviation = $120

            n = sample of students = 19

            [tex]\mu[/tex] = population mean

Here for constructing a 95% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.

So, 95% confidence interval for the population mean, [tex]\mu[/tex] is ;

P(-2.101 < [tex]t_1_8[/tex] < 2.101) = 0.95  {As the critical value of t at 18 degrees of

                                               freedom are -2.101 & 2.101 with P = 2.5%}  

P(-2.101 < [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] < 2.101) = 0.95

P( [tex]-2.101 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]{\bar X-\mu}[/tex] < [tex]2.101 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95

P( [tex]\bar X-2.101 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]\mu[/tex] < [tex]\bar X+2.101 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95

95% confidence interval for [tex]\mu[/tex] = [ [tex]\bar X-2.101 \times {\frac{s}{\sqrt{n} } }[/tex] , [tex]\bar X+2.101 \times {\frac{s}{\sqrt{n} } }[/tex] ]

                        = [ [tex]\$390-2.101 \times {\frac{\$120}{\sqrt{19} } }[/tex] , [tex]\$390+2.101 \times {\frac{\$120}{\sqrt{19} } }[/tex] ]

                        = [$332.16, $447.84]

(A)  Therefore, a 95% confidence for the population mean is [$332.16, $447.84] .

(B) If the confidence level in part (a) changed from 95% to 99%, then the margin of error for the confidence interval which is [tex]Z_(_\frac{\alpha}{2}_) \times \frac{s}{\sqrt{n} }[/tex] would increase because of an increase in the z value.

(C) If the sample size in part (a) changed from 19 to 22, then the margin of error for the confidence interval which is [tex]Z_(_\frac{\alpha}{2}_) \times \frac{s}{\sqrt{n} }[/tex]  would decrease because as denominator increases; the whole fraction decreases.

(D) We are given that to estimate the proportion of students who purchase their textbooks used, 500 students were sampled. 210 of these students purchased used textbooks.

Firstly, the pivotal quantity for finding the confidence interval for the population proportion is given by;

                             P.Q.  =  [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex]  ~ N(0,1)

where, [tex]\hat p[/tex] = sample proportion students who purchase their used textbooks = [tex]\frac{210}{500}[/tex] = 0.42    

            n = sample of students = 500

            p = population proportion

Here for constructing a 99% confidence interval we have used a One-sample z-test statistics for proportions

So, 99% confidence interval for the population proportion, p is ;

P(-2.58 < N(0,1) < 2.58) = 0.99  {As the critical value of z at 0.5%

                                               level of significance are -2.58 & 2.58}  

P(-2.58 < [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < 2.58) = 0.99

P( [tex]-2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < [tex]{\hat p-p}[/tex] < [tex]2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.99

P( [tex]\hat p-2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < p < [tex]\hat p+2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.99

99% confidence interval for p = [ [tex]\hat p-2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] , [tex]\hat p+2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ]

= [ [tex]0.42 -2.58 \times {\sqrt{\frac{0.42(1-0.42)}{500} } }[/tex] , [tex]0.42 +2.58 \times {\sqrt{\frac{0.42(1-0.42)}{500} } }[/tex] ]

= [0.363, 0.477]

Therefore, a 99% confidence interval for the proportion of students who purchase used textbooks is [0.363, 0.477]  .

Answer:

To evaluate an algebraic expression, you have to substitute a number for each variable and perform the arithmetic operations. In the example above, the variable x is equal to 6 since 6 + 6 = 12. If we know the value of our variables, we can replace the variables with their values and then evaluate the expression.

Step-by-step explanation:

Evaluate Algebraic Expressions. ... To evaluate an algebraic expression means to find the value of the expression when the variable is replaced by a given number. To evaluate an expression, we substitute the given number for the variable in the expression and then simplify the expression using the order of operations.

Step-by-step explanation:

I used an app called DESMOS It Is usually super helpful!!!

Answer: a) 0.1095     b) 0.0095

Step-by-step explanation:

Given : The deck for a card game contains 30 cards.

10 are red, 10 yellow, 5 blue, and 1 green, and 4 are wild cards.

Each player is randomly dealt a five-card hand.

Number of ways to choose 5 cards out of 30 = [tex]C(30,5)=\dfrac{30!}{5!25!}=142506[/tex]

a)  Cards other than wild card = 30-4=26

Number of ways to choose exactly two wild cards = [tex]C(26,3)\timesC(4,2)[/tex]

[tex]=\dfrac{26!}{3!23!}\times\dfrac{4!}{2!2!}\\\\=15600[/tex]

Probability that a hand will contain exactly two wild cards = [tex]\dfrac{15600}{142506}=0.1095[/tex]

b) Number of ways to choose two wild cards, two red cards, and one blue cards = [tex]C(4,2)\times C(10,2)\times C(5,1)[/tex]

[tex]=\dfrac{4!}{2!2!}\times\dfrac{10!}{2!8!}\times5=1350[/tex]

Probability that a hand will contain two wild cards, two red cards, and one blue cards = [tex]\dfrac{1350}{142506}=0.0095[/tex]

Answer:

Step-by-step explanation:

Let the number to be found be x

The product of a number and 3 is written as

15 minus twice the number is written as

Now equate the two statements

That's

3x = 15 - 2x

Group like terms

3x + 2x = 15

5x = 15

Divide both sides by 5

the final answer is

Hope this helps you

Answer:

Step-by-step explanation:

Distance walked by Arthur = 5/8 miles

Distance ride  by Jonathan = 8 times that of Arthur

it means that Distance rode on bus by Jonathan is 8 multiplied by Distance walked by Arthur

Distance rode on bus by Jonathan = 8 * Distance walked by Arthur

Distance rode on bus by Jonathan = 8 * 5/8 = 5 Miles Answer

Answer:

x = 10

Step-by-step explanation:

[tex]x = 3 \times 2 + 4[/tex]

[tex]x = 6 + 4[/tex]

[tex]x = 10[/tex]

Answer:

The number of ways is  [tex]\left n} \atop {}} \right. P_r = 336[/tex]

Step-by-step explanation:

From the question we are told that

   The number of tickets are   [tex]n = 8[/tex]

    The number of finalist are [tex]r =3[/tex]

Generally the number of way by which this winners can be drawn and arrange in the order of   [tex]1^{st} , \ 2nd , \ 3rd[/tex]    is mathematically represented as

             [tex]\left n} \atop {}} \right. P_r = \frac{n\ !}{(n-r) !}[/tex]

substituting values

             [tex]\left n} \atop {}} \right. P_r = \frac{ 8!}{(8-3) !}[/tex]

           [tex]\left n} \atop {}} \right. P_r = \frac{ 8* 7*6*5*4*3*2*1}{ 5*4*3*2*1}[/tex]

           [tex]\left n} \atop {}} \right. P_r = 336[/tex]

Answer:

D

Step-by-step explanation:

(b-2)(b-8)+4=0

b^2-10b+16+4=0

b^2-10b+20=0

Product of roots is given by c/a=20. So the answer is 20

Answer:

[tex]\Large \boxed{\sf \bf \ \ y=\dfrac{1}{16}(a-3)^2-2 \ \ }[/tex]

Step-by-step explanation:

Hello, please consider the following.

When the parabola equation is like

[tex]y=a(x-h)^2+k[/tex]

The vertex is the point (h,k) and the focus is the point (h, k+1/(4a))

As the vertex is (3,-2) we can say that h = 3 and k = -2.

We need to find a.

The focus  is (3,2) so we can say.

[tex]2=-2+\dfrac{1}{4a}\\\\\text{*** We add 2. ***}\\\\\dfrac{1}{4a}=2+2=4\\\\\text{*** We multiply by 4a. ***}\\\\16a=1\\\\\text{*** We divide by 16. ***}\\\\a=\dfrac{1}{16}[/tex]

So an equation for the parabola is.

[tex]\large \boxed{\sf y=\dfrac{1}{16}(a-3)^2-2 }[/tex]

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

Answer:

1. Jan checks the weather.  It is 27 degrees outside.  Jan did chores for two hours.  After Jan was done, she checked the weather again.  The temperature had decreased 11 degrees.

2. (See screen shot below.)

Step-by-step explanation:

1.  It doesn't have to be as complicated as I made it.  You can just say that the weather started out with 27 degrees, and decreased later on.  Remember, decreased means subtracted and 27+(-11) is the same as 27-11 because when a + and - are together - always wins.  So no.1 wants you to say something got subtracted.

2. On the number line, make a dot at 29 because it said it was 29 degrees.  Then drag the dot at the number 29 to 13 because it said it decreased 16, so it is 19 minus 16 which is 13.

Answer:

4x

Step-by-step explanation:

Given:

√x • 4√x

Required:

Simplify in rational exponent form

SOLUTION:

Recall => [tex] \sqrt{a} = a^{\frac{1}{2}} [/tex]

Thus,

[tex] \sqrt{x}*4\sqrt{x} [/tex] can be expressed in exponent form as [tex] x^{\frac{1}{2}}*4x^{\frac{1}{2} [/tex]

When multiplying 2 bases having exponents together, their exponents should be added together, while you multiply the bases. I.e. [tex]x^m*x^n = x^{m+n }[/tex]

[tex] = x*4^{\frac{1}{2}+\frac{1}{2} [/tex]

[tex] = 4x^{1} = 4x [/tex]

The answer is 4x

Step-by-step explanation:

It is given that,

5.39 jings =15.4 hings  ....(1)

4.9 hings = 2.8 gings ...(2)

From equation (2), the value of 1 ging is :

[tex]1\ \text{ging} = \dfrac{4.9}{2.8}\ \text{hing}\ .....(3)[/tex]

From equation (1), the value of 1 jing is :

[tex]1\ \text{jing} = \dfrac{15.4}{5.39}\ \text{hing}\ .....(4)[/tex]

From equation (3) and (4), we get :

[tex]\dfrac{\text{1 ging}}{\text{1 jing}}=\dfrac{4.9}{2.8}\times \dfrac{5.39}{15.4}\\\\\dfrac{\text{1 ging}}{\text{1 jing}}=\dfrac{49}{80} \\\\1\ \text{ging}=\dfrac{49}{80}\ \text{ jings}[/tex]

Hence, the correct option is (g) "49/80"

Answer:

Within the factors hindering expression in music, tempo is the most important number of factors such as your mood.

Step-by-step explanation:

If one wants to convey a message, they should try these:

a) Use real life

b) introduce symbolism

c) convey sensory disruption, e.t.c.

Hope these helps.

Answer:

Step-by-step explanation:

Decay of carbon - 14 is exponential in nature . It decays as follows .

[tex]N=N_0e^{-\lambda t}[/tex]  λ is called decay constant .

λ = .693 / T where T is half life .

Half life of carbon-14 is 5700 years

λ = .693 / T

= .693 / 5700

= 12.158 x 10⁻⁵ year⁻¹

[tex]N=N_0e^{-\lambda t}[/tex]

N = .71 N₀

[tex].71 N_0 =N_0e^{-\lambda t}[/tex]

[tex].71 =e^{-\lambda t}[/tex]

Taking ln on both sides

ln .71 = - λ t

ln .71 = - 12.158 x 10⁻⁵  t

-0.3425 =  - 12.158 x 10⁻⁵  t

t = .3425 / 12.158 x 10⁻⁵

2817  years .

Answer:

The (y^2 ) or (y^–2) It is not clear, I solved it in both ways (y^2) and (y^-2) .^_^

[tex] - 7 {x }^{2} - 5 + {y}^{2} \\ - 7( { - 2}^{2} ) - 5 + {4}^{2} \\ - 7( - 4) - 5 + 16 \\ 28 - 5 + 16 \\ = 39[/tex]

_______o_____o_______

[tex] - 7 {x }^{2} - 5 + {y}^{ - 2} \\ - 7( { - 2}^{2} ) - 5 + {4}^{ - 2} \\ - 7( - 4) - 5 + \frac{1}{16} \\ 28 - 5 + \frac{1}{16} \\ = 23.06[/tex]

I hope I helped you^_^

Answer:

B

Step-by-step explanation:

Since the power is negative, you automatically know it has to be a or b, because the only way it would be negative is if it was brought from the denominator to the numerator.

The answer is B, because the numerator of the power, is what is inside the square root, while the denominator is what is outside the square root.

Answer

Is it C I may have done my math wrong lol

Step-by-step explanation:

Answer:

The width is  [tex]w = 282.8[/tex]

Step-by-step explanation:

From the question we are told that

  The sample size is n =  50

  The  population standard deviation is  [tex]\sigma = \$ 1000[/tex]

   The sample size is  [tex]\= x = \$ 15,000[/tex]

Given that the confidence level is  90%  then the level of significance can be mathematically represented as

             [tex]\alpha = 100 - 90[/tex]  

             [tex]\alpha = 10 \%[/tex]  

              [tex]\alpha = 0.10[/tex]

Next we obtain the critical value of  [tex]\frac{\alpha }{2}[/tex] from the  normal distribution table, the value is  

             [tex]Z_{\frac{0.10 }{2} } = 1.645[/tex]

Generally the margin of error is mathematically represented as

               [tex]E = Z_{\frac{0.10}{2} } * \frac{\sigma }{\sqrt{n} }[/tex]

substituting values

                 [tex]E = 1.645 * \frac{1000 }{\sqrt{50 }}[/tex]

=>                [tex]E = 141.42[/tex]

  The width of the 90%  confidence level is mathematically represented as

                      [tex]w = 2 * E[/tex]

substituting values

                       [tex]w = 2 * 141.42[/tex]

                       [tex]w = 282.8[/tex]

Answer:

The area of ΔABC= 6.667 square units

Step-by-step explanation:

ΔABC is similar to ΔMNO.

The scale factor from ΔMNO to ΔABC is 3∕2

the area of ΔMNO is 10 square units,

The area of ΔABC/the area of ΔMNO

= 2/3

The area of ΔABC/10= 2/3

The area of ΔABC= 2/3 * 10

The area of ΔABC= 20/3

The area of ΔABC= 6 2/3

The area of ΔABC= 6.667 square units

Answer:

22.5 square units

Step-by-step explanation:

i multiplied 10 by 2 to get 20 and went with the closest answer and got it right.

i dont know how to do math but i guess it worked

Answer:

Bro 1st expression is in simplest form and 2nd in simplest is 3/2

Step-by-step explanation:

If you like my answer than please mark me brainliest

Answer:

(5/2)*(9/6)

three can go into the fraction(9/6) giving(3/2)

(5/2)*(3/2)=15/4

mark as brainliest

Answer:

By finding LCM of 9 and 12 the answer is 36

Step-by-step explanation:

If you like my answer than please mark me brainliest thanks

Answer:

stdev= 2.366431913

Step-by-step explanation:

10  stdev= 2.366431913

17  

12  

14  

12  

Answer:

y-5=3(x+1)

Step-by-step explanation:

we use the point-slope formula to plug all of our values in.

[tex]y-y_{1}=m(x-x_{1})[/tex]

Answer:

1 solution

Step-by-step explanation:

the two equations only cross once

The system of equations may have either 2 or 1 solution, but we cannot determine the exact number of solutions without further information or analysis.

We have,

The given system of equations consists of two equations in two variables:

y = (-1/3)x + 7 _______(1)

y = -2x³ + 5x² + x - 2 _______(2)

To find the solutions of the system, we need to find the values of x and y that satisfy both equations simultaneously.

Since both equations are in the form y = ...,

we can set the expressions on the right-hand sides of the equations equal to each other:

(-1/3)x + 7 = -2x³ + 5x² + x - 2

Rearranging and simplifying, we get:

2x³ - 5x² - (2/3)x + 9 = 0

To solve for x, we can use factoring or the rational root theorem.

However, the polynomial on the left-hand side of the equation does not appear to have any rational roots or easily factorable forms.

Therefore, to determine the number of solutions,

we can use Descartes' rule of signs to find the possible number of positive and negative roots of the polynomial:

The number of positive roots is either equal to the number of sign changes in the coefficients or less than it by an even integer.

There are two sign changes in the coefficients, so there can be either 2 or 0 positive roots.

The number of negative roots is either equal to the number of sign changes in the coefficients or less than it by an even integer.

There is one sign change in the coefficients, so there can be either 1 or 0 negative roots.

Since the sum of the possible number of positive and negative roots is either 2 or 1, the total number of solutions is either 2 or 1.

Therefore,

The system of equations may have either 2 or 1 solution, but we cannot determine the exact number of solutions without further information or analysis.

Learn more about solutions of equations here:

https://brainly.com/question/545403

#SPJ7

Answer:

-2,  (-5 is extraneous)

Step-by-step explanation:

assuming √(x+6) -4 =x

√(x+6) = x+4

square both side

x+6 = (x+4)^2

x+6 = x^2+8x+16

x^2+7x+10=0

(x+2)(x+5) = 0

x = -2, -5

put -5 back into org equation and it is not true

√(-5+6) -4 ≠ -5

Answer:

g(1) = 1

Step-by-step explanation:

g(1) with x = 1 corresponds to x ≠ - 2, - 1 with g(x) = x³ - x² + 1 , then

g(1) = 1³ - 1² + 1 = 1 - 1 + 1 = 1

Answer:

g ( 1 ) = 1

Step-by-step explanation:

→ Substitute x = 1 into x³ - x² + 1

( 1 ) ³ - ( 1 )² + 1

→ Simplify

1 - 1 + 1 = 1

y = a(x  + 1.5)^2 - 12.5

y intercept is (0,-8) so:-

-8 = a(0+1.5)^2 - 12.5

-8 = 2.25a - 12.5

a =  4.5/ 2.25 = 2

so we have  

y  = 2 ( x +1.5)^2 - 12.5

solving for x  when y = 0:-

(x + 1.5)^2 = 12.5/2 = 6.25

taking sqrt's  x + 1.5  = +/- 2.5

x =  -4,   1

so the x intercepts are (-4,0) and (1,0)

Answer:

y = –1∕4(x – 8)^2 – 1

Step-by-step explanation:

I took the exam and  got  it  right.

Answer: 3

Step-by-step explanation:

first, we know that:

1 + 2 + 3 + 4 +5 +6 = 21

Now, which two numbers we should take out in order to have 15?

we can remove the 2 and the 4, or the 1 and the 5.

so here we have two possibilities, 2 and 4 are opposite, or 1 and 5 are opposite (they are located in opposite faces of the die)

in the other arrange, we have that removing two numbers we should get 12.

in order to reach 12, we should remove two numbers that add 9 together.

those can be 4 and 5, or 6 and 3.

Now, notice that in the first restriction we have that:

Or 2 and 4 are opposite,

or 1 and 5 are opposite.

So 4 and 5 can never be opposite, so we should have that 6 and 3 are opposite.

Then we can affirm that the value that appears in the face opposite to the 6, is the 3.