helppppp please I will give brainliest​

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:

open

Step-by-step explanation:

Answer:

This is True.

Step-by-step explanation:

16-7=9

5+4=9

same ting

Answer: Approximately 51 years.

Step-by-step explanation: A population grows by changing exponentially over time, which can be mathematically demonstrated as:

[tex]P=P_{0}e^{rt}[/tex]

where

P is the population after time

P₀ is initial population, when time = 0

r is a percentage rate of growth

t is time passed

In this case, we have to calculate the amount of time it has passed for a population to double, so [tex]P=2P_{0}[/tex]:

[tex]2P_{0}=P_{0}e^{0.0135t}[/tex]

[tex]e^{0.0135t}=2[/tex]

[tex]ln(e^{0.0135t})=ln2[/tex]

Using Logarithm Rule [tex]ln(e^{k})=k[/tex]:

[tex]0.0135t=0.693[/tex]

t = 51.34

For a population with rate of 1.35%, it will take approximately 51 years to double.

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 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:

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:

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.

Learn more about residual plots, click;

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Answer:

The answer should be x = -7/8 but it doesn't say that for any of the choices

Step-by-step explanation:

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)

Learn more about coordinates here:

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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:

[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

Read more at; https://brainly.com/question/103282

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:

5840

Step-by-step explanation:

16 x 365 is 5840

Answer:

5,840

Step-by-step explanation:

16x365=?

16x365=5,840

Answer:

27200

Step-by-step explanation:

Answer:

y=-2

Step-by-step explanation:

its like in the paper sorry it if crops out

Answer:

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

Step-by-step explanation:

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:

65.5

Step-by-step explanation:

Answer:

65.5

Step-by-step explanation:

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:

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:

375/1,000

Step-by-step explanation:

3/8=0.375

375/1,000 =0.375

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:

False

Explanation

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

Answer:

Step-by-step explanation: 1,872

Answer: 1,872

Step-by-step explanation:

Answer:

0.7143

- You know the minimum possible grade of the student

- You want to find out the probability that that grade which is greater than 72 is also greater than 84

- Expect the answer to be 0.7143

- The explanation/steps is given below

- The answer seems (and is) reasonable. You only created a new lower limit.

Step-by-step explanation:

Distribution Type: Normal

Mean: 78

Standard deviation: 36

Range of marks: [78 - 36], [78 + 36]  = [42 to 114]

If you know that a student's grade is greater than 72, what is the probability that it's greater than 84?

In this case, the full probability level is between 72 and the upper limit of 114 (instead of between 42 and 114). First, find the fraction of this probability.

[114 - 72] ÷ [114 - 42]  = 42/72  = 0.5833

So, the probability of a student's mark falling between 72 and 114 is 0.5833.

Now making this a whole interval, 114 - 72 = 42

What fraction of this interval of 42 will bear marks between 84 and 114?

[114 - 84]  = 30

30/42  = 0.7143

Because of the first part of the question "If you know (are sure) that a student's grade is greater than 72...", your answer stops at 0.7143, since 72 was used as the lower limit.

Answer:C

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

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