can u pls help me with this question ​

Answer:

d=-124

Step-by-step explanation:

To find the discriminant use the equation b^2-4ac

So, 20^2-4(-131)(-1)

400-524= -124

d=-124

Answer:

A is the correct answer

Step-by-step explanation:

The not correct statement about residual plot is If there is an obvious pattern, the model is probably reasonable.

A residual plot shows the difference between the observed response and the fitted response values.

Given that, Which statement about residual plots is not true

In the given options,

If there is an obvious pattern, the model is probably reasonable, this option is not correct because, The pattern in the residual plot suggests that predictions based on the linear regression line will result in greater error as we move from left to right through the range of the explanatory variable.

So, it is not needed if there is an obvious pattern, then the model is probably reasonable,

Hence, the not correct statement about residual plot is If there is an obvious pattern, the model is probably reasonable.

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Answer:

1)  10

2) (not enough info) I got 6/7

3) 12

4) 10

Step-by-step explanation:

Find a GCF and find the numerator.

Answer:

False

Explanation

The x-intercept of a line occurs when the line intersects with the x-axis.

Answer: 4

Step-by-step explanation:

6/9 = m/6  We can multiply both sides of the equation by 6 to solve for m

so we get 36/9 = m. m = 4

Answer:

The sample size 'n' = 26

Step-by-step explanation:

Explanation:-

Given a researcher wishes to estimate within $5 the average repair cost of for a refrigerator

Given estimate "E" = $5

The  estimate within  the average is determined by

                [tex]E = \frac{Z_{0.10}S.D }{\sqrt{n} }[/tex]

 Level of significance    ∝ = 90 % or 10%

                                            = 0.90 or o.10

Z₀.₁₀ = 1.645

                                 [tex]E = \frac{Z_{0.10}S.D }{\sqrt{n} }[/tex]

                             [tex]5 = \frac{1.645 X15.50 }{\sqrt{n} }[/tex]

                        √n =  [tex]\frac{25.49}{5} = 5.099[/tex]

Squaring on both sides , we get

                        n = 26

Conclusion:-

The sample size 'n' = 26

Answer:

The rate of change relates the change in population to the change in time.  The population increased by 2212−1900=312 people over the four-years.  To find the rate of change, divide the change in the number of people by the number of years.

2212−19004=3124

3124/4 =78

So the population increased by 78 people per year.

Because we are told that the population increased, we would expect the slope to be positive.  This positive slope we calculated is therefore reasonable.

Answer:

[tex]\frac{dy}{dx}[/tex] = 3 cos² y ⇒ B

Step-by-step explanation:

∵ 3x - tan(y) = 4

∵ The differentiation of tan(y) with respect to x is sec² y · dy/dx

∵ The differentiation of 3x with respect to x is 3

∵ the differentiation to 4 with respect to x is 0

∴ d/dx [3x - tan(y) = 4] is 3 - sec² y · dy/dx = 0

∵ 3 - sec²(y) · dy/dx = 0

→ Subtract 3 from both sides

∴ - sec² y · dy/dx = -3

→ Divide both sides by -1

∴ sec² y · dy/dx = 3

→ Divide both sides by sec²(x)

∴ [tex]\frac{dy}{dx}=\frac{3}{sec^{2}y}[/tex]

→ Remember [tex]\frac{1}{secy}[/tex] = cos y

∵ [tex]\frac{1}{sec^{2}y}[/tex] = cos² y

∴  [tex]\frac{3}{sec^{2}y}[/tex] = 3 cos² y

∴ [tex]\frac{dy}{dx}[/tex] = 3 cos² y

dy/dx of 3x – tan y = 4 in terms of y is;

dy/dx = 3cos²y

We are given;

3x - tan y = 4

Let's differentiate in terms of y to get;

3 - sec²y(dy/dx) = 0

This is because the derivative of tan y in terms of y is sec²y(dy/dx).

Thus, using addition property of equality, we have;

3 = sec²y(dy/dx)

Now, in trigonometric ratios;

sec y = 1/cos y

Thus;

sec²y = 1/cos²y

Therefore;

3 = (1/cos²y) (dy/dx)

Thus;

dy/dx = 3cos²y

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Answer:

a

 The upper bound of the 99% prediction level is [tex] 98.2  [/tex]  

b

 The  95% confidence interval is [tex]9.7383 <  \mu < 10.2617 [/tex]

Step-by-step explanation:

Considering first question

From the question we are told that

   The sample size is  n  =  30  

   The sample mean is  [tex]\= x = 96.2\%[/tex]

   The standard deviation is [tex]s = 0.8\%[/tex]

Generally the degree of freedom is mathematically represented as

        [tex]df = n - 1[/tex]

=>      [tex]df = 30 - 1[/tex]

=>      [tex]df = 29[/tex]

From the question we are told the confidence level is  99% , hence the level of significance is    

      [tex]\alpha = (100 - 99 ) \%[/tex]

=>   [tex]\alpha = 0.01[/tex]

Generally from the t distribution table the critical value  of   at a degree of freedom of is  

   [tex]t_{\alpha , 29} = 2.462[/tex]

Generally the  99%  prediction level is mathematically represented as

      [tex]\= x \pm [(t_{\alpha  , df }) * s * (\sqrt{1 + \frac{1}{ n} } )}] [/tex]

Generally the upper bound of the 99%  prediction level is mathematically represented as

      [tex]\= x + [(t_{\alpha  , df }) * s * (\sqrt{1 + \frac{1}{ n} } )}] [/tex]  

=>    [tex] 96.2 + (2.462 ) * 0.8 * (\sqrt{1 + \frac{1}{ 30} } )}] [/tex]  

=>    [tex] 98.2  [/tex]  

Considering second question

 Generally the sample is mathematically represented as

             [tex]\= x = \frac{\sum x_i}{n}[/tex]

=>           [tex]\= x = \frac{ 9.8 + 10.2 + \cdots +9.6 }{7}[/tex]  

=>           [tex]\= x = 10[/tex]    

Generally the standard deviation  is mathematically represented as

           [tex]\sigma = \sqrt{ \frac{ \sum ( x_ i - \= x)}{n-1} }[/tex]

=>        [tex]\sigma = \sqrt{ \frac{ ( 9.8 -10)^2 + ( 10.2 -10)^2 + \cdots + ( 9.6 -10)^2 }{7-1} }[/tex]

=>        [tex]\sigma = 0.283[/tex]

Generally the degree of freedom is mathematically represented as

      [tex] df =  n- 1 [/tex]

=>    [tex] df =  7- 1 [/tex]

=>    [tex] df =  6 [/tex]

From the question we are told the confidence level is  95% , hence the level of significance is    

      [tex]\alpha = (100 - 95 ) \%[/tex]

=>   [tex]\alpha = 0.05[/tex]

Generally from the t distribution table the critical value  of   at a degree of freedom of  is  

   [tex]t_{\frac{\alpha }{2} , 6 } =  2.447[/tex]

Generally the margin of error is mathematically represented as  

      [tex]E = t_{\frac{\alpha }{2} , 6 } *  \frac{\sigma }{\sqrt{n} }[/tex]

=>    [tex]E =2.447*    \frac{0.283 }{\sqrt{7} }[/tex]

=>    [tex]E =0.2617[/tex]

Generally 95% confidence interval is mathematically represented as  

      [tex]\= x -E <  \mu <  \=x  +E[/tex]

=>   [tex]10 -0.2617 <  \mu < 10 + 0.2617[/tex]

=>   [tex]9.7383 <  \mu < 10.2617 [/tex]

Answer:0.916

The decimal multiplier to decrease by 8.4% is 0.916.

Step-by-step explanation:

Answer:

27200

Step-by-step explanation:

Answer:C

Step-by-step explanation: slope of 0 will always be horizontal

Answer:

See Attachment.

General Formulas and Concepts:

Algebra I

Slope-Intercept Form: y = mx + b

Step-by-step explanation:

Step 1: Define variables

Slope m = -1

y-intercept b = 3

Step 2: Write linear equation

Substitute into general form.

Slope-Intercept Form:   y = -x + 3

Step 3: Graph

Answer:

is this question complete? there is nothing after the word “that”

Step-by-step explanation:

Answer:

not sure i it is one of these answers but if so , it d

Step-by-step explanation:

When performing division by repeated subtraction method, an equal

amount is subtracted from the dividend several times.

The best choice for the first number to subtract is the the option; 870

Reasons:

Dividing 956 by 87 and subtracting 10 each time, by subtracting 10 87 times gives;

956 - 87 × 10¹ = 86

From which we get;

The 870 which is the part product is subtracted first to get a remainder of

86 which is less than 87.

Therefore; using powers of 10, the best choice for the first number to

subtract in the division problem 956 ÷ 87 is 87 × 10 = 870.

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Answer:

65.5

Step-by-step explanation:

Answer:

65.5

Step-by-step explanation:

Answer:

7/20

Step-by-step explanation:

you put 35/100 and reduce into a simpilest form

Hope this helps!

C. October 15

Answer: A.) 10x + 15

Step-by-step explanation:

You would distribute (multiply) the 5 to the 2x which would then make it 10x and you would distribute (multiply) the 5 to the 3 which would then make it 15. Because the 5 is a positive number the sign stays the same.

Therefore, 10x + 15 is your answer.

Answer:

open

Step-by-step explanation:

Answer:

This is True.

Step-by-step explanation:

16-7=9

5+4=9

same ting

Answer:

here you go this is for confirmation

Step-by-step explanation:

Answer:

The backpack weighs more

Step-by-step explanation:

9.5kg = 20.94391 lbs

Answer:

a backpack that weighs 9.5kg

Step-by-step explanation:

kilogram (kg) is stated to be 2.2 times heavier than a pound

Answer:

(8,1)

Step-by-step explanation:

(8,1) you have to add do to the same to B

Pont B is located at coordinates at the line AB (8, 1)

A pair of numbers called coordinates are used to locate a point or a form in a two-dimensional plane. The x-coordinate and the y-coordinate are two numbers that define a point's location on a 2D plane.

Given, The midpoint of AB is M(6,-3). If the coordinates of A are (4, - 7)

From the general formula of midpoints of a line

coordinates of midpoint = ((x₂ + x₁)/2, (y₂ + y₁)/2)

where,

(x₁, y₁) are the coordinates of A

(x₂, y₂) are the coordinates of B

And in our case Coordinates of the midpoint are (6, -3)

Thus,

6 = (4 + x₂)/2

x₂ = 8

-3 = (-7 + y₂)/2

y₂ = 1

therefore, the coordinates of Pont B at line AB are (8, 1)

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Answer:

Value of x=4 and y=-13/3

Step-by-step explanation:

We need to solve the systems of equations

[tex]5x+3y=7 \ and \ \frac{3}{2}x-\frac{3}{4}y =9\frac{1}{4}[/tex]

Solving using substitution method:

Let:

[tex]5x+3y=7---eq(1) \\ \frac{3}{2}x-\frac{3}{4}y =9\frac{1}{4}---eq(2)[/tex]

Find value of x from eq(1) and put in eq(2)

[tex]5x+3y=7\\5x=7-3y\\x=\frac{7-3y}{5}[/tex]

Put value of x in eq(2)

[tex]\frac{3}{2}(\frac{7-3y}{5}) -\frac{3}{4}y =\frac{37}{4}\\\frac{21-9y}{10} -\frac{3}{4}y =\frac{37}{4}\\Taking \ LCM\\\frac{21*2-9y*2-3y*5}{20} =\frac{37}{4}\\\frac{42-18y-15y}{20} =\frac{37}{4}\\42-33y=\frac{37}{4}*20\\42-33y=185\\-33y=185-42\\-33y=143\\y=\frac{143}{-33}\\y=-\frac{13}{3}[/tex]

Now, finding value of x by putting value of y in eq(1)

[tex]x=\frac{7-3y}{5}\\x= \frac{7-3(-\frac{13}{3}) }{5}\\x=\frac{7+13}{5}\\x=\frac{20}{5}\\x=4[/tex]

So, Value of x=4 and y=-13/3

Answer:

18

Step-by-step explanation:

If we know she will have a 25% discount, we know she will only pay 75%. So you divide by 4 and get 6. So now, If we subtract 25% (6), our 75% will be 18.

Answer:

It's 18

Step-by-step explanation:

25 percent of 24 is 6 dollars, subtract 6 from 24, you get 18, your welcome :D

Answer:

i got negative 108

Step-by-step explanation:

i got this because just put it in a porportion like x/y = x/?

then plug in the numbers it gives you. so it should look like this 5/-45 = 12/?

then multiply 12 and -45 and then divide by 5. you should get -108

pls mark branliest