In a survey, 30 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $35 and standard deviation of $17. Construct a confidence interval at a 95% confidence level.

Answer:

(-2,0)

Step-by-step explanation:

The x intercept is the value when it crosses the x axis ( the y value is zero)

x = -2 and y =0

(-2,0)

Answer:

it simple as look

Step-by-step explanation:

He y I a m r a v I t ha n k S

Wowowowowowowowowk

Answer:

Step-by-step explanation:

Assuming the system is solvable in the first place, create an augmented matrix of coefficients from the equations. Then put the matrix into reduced row echelon form.

Example is attached.

"Demonstrate by solving the following system."

You need to provide the system of equations.

===============================================

Explanation:

Add up the values to get

1.96+1.81+1.97+1.83+1.87+1.84+1.85+1.94+1.96+1.81+1.86+1.95+1.89= 24.54

Then divide over 13 (the number of values) to get 24.54/13 = 1.8876923 which is approximate.

So the mean is approximately 1.8876923

---------------------

Now make a spreadsheet as shown below

We have the first column as the x values, which are the original numbers your teacher provided. The second column is of the form (x-M)^2, where M is the mean we computed earlier. We subtract off the mean and square the result.

After we compute that column of (x-M)^2 values, we add them up to get what is shown in the highlighted yellow cell at the bottom of the column.

That sum is approximately 0.04403076924

Next, we divide that over n-1 = 13-1 = 12

0.04403076924 /12 = 0.00366923077

That is the sample variance. Apply the square root to this to get the sample standard deviation. This is the point estimate of the population standard deviation. As the name implies, it works for samples that estimate population parameters.

sqrt(0.00366923077) = 0.06057417576822

This rounds to 0.061 which is the final answer.

Solution :

Given information :

A sample of n = 10 adults

The mean failure was 24 and the standard deviation was 3.2

a). The formula to calculate the 95% confidence interval is given by :

[tex]$\overline x \pm t_{\alpha/2,-1} \times \frac{s}{\sqrt n}$[/tex]

Here, [tex]$t_{\alpha/2,n-1} = t_{0.05/2,10-1}$[/tex]

                       = 2.145

Substitute the values

[tex]$24 \pm 2.145 \times \frac{3.2}{\sqrt {10}}$[/tex]

(26.17, 21.83)

When the [tex]\text{sampling of the same size}[/tex] is repeated from the [tex]\text{population}[/tex] [tex]n[/tex] infinite number of [tex]\text{times}[/tex], and the [tex]\text{confidence intervals}[/tex] are constructed, then [tex]95\%[/tex] of them contains the [tex]\text{true value of the population mean}[/tex], μ in between [tex](26.17, 21.83)[/tex]

b). The formula to calculate 95% prediction interval is given by :

    [tex]$\overline x \pm t_{\alpha/2,-1} \times s \sqrt{1+\frac{1}{n}}$[/tex]

   [tex]$24 \pm 2.145 \times 3.2 \sqrt{1+\frac{1}{10}}$[/tex]

   (31.13, 16.87)

Answer:

Step-by-step explanation:

Answer:

Step-by-step explanation:

Parabola: y=2x²

Let say (a,b) the focus and y=k the directrix.

[tex]formula\ to\ use:\ \boxed{y=\dfrac{(x-a)^2}{2(b-k)} +\dfrac{b+k}{2} }\\\\\left \{\begin {array}{ccc}a&=&0\\2&=&\dfrac{1}{2(b-k)} \\\dfrac{b+k}{2} &=&0\\\end {array} \right.\\\\\\\left \{\begin {array}{ccc}a&=&0\\b-k&=&\dfrac{1}{4} \\b+k &=&0\\\end {array} \right.\\\\\\\left \{\begin {array}{ccc}a&=&0\\b&=&\dfrac{1}{8} \\k &=&\dfrac{-1}{8} \\\end {array} \right.\\\\\\focus=(0,\dfrac{1}{8} )\\\\directrix:\ y=\dfrac{-1}{8}[/tex]

Answer:

4 units

Step-by-step explanation:

A'B' = 2 × AB

8 = 2×AB

AB = 8/2 = 4

Answer:

16 units

Step-by-step explanation:

The triangle will get bigger because it has a scale factor that is greater than 1.

k=scale factor

k<1=reduction

k>1=enlargement

Answer:

C. 2x+11

Step-by-step explanation:

2x+11≈21 -55

2x+11≈21 -55

2x+11≈21 -55

2x+11≈21 -55

2x+11≈21 -55

Answer:

1/256

Step-by-step explanation:

[tex]4^{-4}[/tex]

[tex](1/4)^{4}[/tex]

=> 1/256

Answer:

Step-by-step explanation:

I assume the sequence is 0, 2, 4, 6

nth term = 2(n-1)

Answer:

The null hypothesis is [tex]H_0: \sigma = 0.3[/tex]

The alternative hypothesis is [tex]H_1: \sigma \neq 0.3[/tex]

Step-by-step explanation:

Test if the tar content of filtered​ 100-mm cigarettes has a standard deviation different from 0.30 ​mg.

At the null hypothesis, we test if the standard deviation is of 0.3, that is:

[tex]H_0: \sigma = 0.3[/tex]

At the alternative hypothesis, we test if the standard deviation is different of 0.3, that is:

[tex]H_1: \sigma \neq 0.3[/tex]

Answer:

[tex]A(x) = 12500(1.054)^x[/tex]

Step-by-step explanation:

Exponential equation for population growth:

Considering a constant growth rate, the population, in x years after 2005, is given by:

[tex]A(x) = A(0)(1 + r)^x[/tex]

In which A(0) is the population in 2005 and r is the growth rate, as a decimal.

The initial population of the town was estimated to be 12,500 in 2005.

This means that [tex]A(0) = 12500[/tex]

The population has increased by about 5.4% per year since 2005.

This means that [tex]r = 0.054[/tex]

So

[tex]A(x) = A(0)(1 + r)^x[/tex]

[tex]A(x) = 12500(1 + 0.054)^x[/tex]

[tex]A(x) = 12500(1.054)^x[/tex]

Answer:

0.5

Step-by-step explanation:

E to E'

(0, 3) to (0, 1.5)  each term of E' is ½ of the corresponding term of E

N to N'

(-1, 1) to (-0.5, 0.5)  each term of N' is ½ of the corresponding term of N

U to U'

(2, -2) to (1, -1)  each term of U' is ½ of the corresponding term of U

V to V'

(1, -3) to (0.5, -1.5)  each term of V' is ½ of the corresponding term of V

Answer:

Perimeter

[tex]202 = x + x + 26 + 4x + 26 + 4x\\202-26-26=10x\\150=10x\\x=15[/tex]

Therefore, the dimensions are

Answer:

b

Step-by-step explanation:

b is  correct.

Answer:

[tex]f(x) = \sqrt{x} + 2 \\ \\ g(x) = {x}^{2} + 1 \\ \\ f{g(x)} = \sqrt{ {x}^{2} + 1 } + 2 \\ \\ g{f(x)} = {( \sqrt{x} + 2 )}^{2} + 1[/tex]

A coefficient is a numerical value that is multiplied with a variable.

[tex]The \: text \: tells \: us \: that \: we \: can \\ predict \: her \: height \: by \: taking \\ her \: age \: in \: months, \: adding \: 75, \\ and \: multiplying \: by  \: \frac{1}{3} . \: So \: our \\ equation \: is [/tex]

[tex]h = (m + 75). \frac{1}{3} [/tex]

(or)

[tex]h = \frac{1}{3} (m + 75)[/tex]

b) Determine her predicted height on her second birthday

To predict Asia’s height on her second birthday, we substitute m=24

into our equation (because 2 years is 24 months) and solve for h.

[tex]h = \frac{1}{3} (24 + 75)[/tex]

[tex]h = \frac{1}{3} (99)[/tex]

[tex]h = 33[/tex]

Asia’s height on her second birthday was predicted to be 33 inches.

The system of inequalities that is graphed is:

y ≤ - (2/3)*x

y < x - 3

So the correct option is B.

First, we can see that for both of the inequalities the shaded part is below the lines.

You also can see that the solid line (correspondent to the symbol ≤) is the one with a negative slope, and the dashed line (correspondent with the line <) is the one with a positive slope.

Only with that, we conclude that the correct option is B.

y ≤ - (2/3)*x

y < x - 3

If you want to learn more about inequalities:

https://brainly.com/question/24372553

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Answer:

In a pair of similar triangles, the corresponding sides are proportional.

Step-by-step explanation:

Corresponding sides touch the same two angle pairs. When the sides are corresponding it means to go from one triangle to another you can multiply each side by the same number.

Answer:

582-600

1,234-1,200

640-600

770-800

1,104-1,100

Answer:

628 mi^3

Step-by-step explanation:

the volume of a cylinder is given by:

V = base area x height

thus,

V = (3.14)(5)^2(8)

V = (3.14)(25)(8)

V = 628 mi^3

the volume of the cylinder is 628 cubic miles

The volume of the cylinder is 628 cubic miles.

We have a cylinder of radius 5 mi and height 8 mi.

We have to find the volume of the figure and round it to nearest tenth.

The volume of cylinder is given by the formula -

Volume [tex]=\pi r^{2} h[/tex]

We can use the above formula to calculate the volume of cylinder. In our case -

r = 5 mi

h = 8 mi

Substituting the values in the formula -

Volume [tex]=\pi\times5^{2}\times 8\\\\[/tex] = 628 cubic miles.

Hence, the volume of the cylinder is 628 cubic miles.

To solve more questions on finding the volume of cylinder, visit the link below -

https://brainly.com/question/16134180?referrer=searchResults

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Answer:

We are given the function:

[tex]f(x)=2x^2-x-10[/tex]

[tex]Here,\\a=2, b=-1,c=-10[/tex]

1. X-intercepts are the points at which the graph of a function intersects or cuts the x-axis. Since the x-intercept always lies on the x-axis, its ordinate or y-coordinate will always be 0. Since the function is quadratic, it will have at most 2 x-intercepts.

In order to find the x intercept, we basically solve for x at y=0:

[tex]f(x)=2x^2-x-10\\As\ y=0,\\0=2x^2-x-10\\2x^2-x-10=0\\ 2x^2-5x+4x-10=0\\x(2x-5)+2(2x-5)=0\\(x+2)(2x-5)=0\\Hence,\\Individually:\\x=-2,\ x=\frac{5}{2}[/tex]

Hence, the x-intercepts of the parabola of f(x) is (-2,0),(2.5,0)

2. The vertex of parabola is determined as maximum or minimum, solely on how it opens. This depends on the nature of the co-efficient of the x^2 term or 'a'. If a is positive the parabola opens upwards (minimum point) and downwards (maximum point) if negative. Hence, here as a=2, the parabola opens upwards and its vertex is minimum.

[tex]Vertex=(\frac{-b}{2a},\frac{-D}{4a})\\Hence,\\D=b^2-4ac\\Substituting\ a=2,b=-1,c=-10:\\D=(-1)^2-4*2*-10=1+80=81\\Hence,\\Vertex\ of\ f(x)=(\frac{-(-1)}{2*2},\frac{-81}{4*2})=(\frac{1}{4},\frac{-81}{8})[/tex]

3. [Please refer to the attachment]

From the graph, we observe that the parabola cuts the x-axis at (-2,0),(2.5,0). Also, its clear that the axis of symmetry passes through [tex](\frac{1}{4},\frac{-81}{8})[/tex], which is its minimum point.

Answer:

A chord of a circle is 9cm long if it's distance from the centre of the circle is 5cm calculate the radius of the circle

Answer:

soory i dont know just report me if you angry

Answer:

1.083

Step-by-step explanation:

Exact form: 13/12

Decimal form: 1.083 (put a line above the 3)

Mixed number form: 1 1/12

9514 1404 393

Answer:

Step-by-step explanation:

For the purpose of selecting the appropriate tile, it is only necessary to figure the real part of the sum or product.

We notice that the second product (-xy) is -1/2 times the first product (2xy). This can let you find the answers on that basis alone. The only tiles with a (-1) : (2) relationship are (-29 -53i) : (58 +106i).

__

The sum -5x +y has a real part of -5(3) +7 = -8.

The sum 2x -3y has a real part of 2(3) -3(7) = 6 -21 = -15.

Hence the sequence of answers needed on the right side is as shown above.

_____

Additional comment

You know that arithmetic operations with complex numbers (multiplication and addition) are identical to those operations performed on any polynomials. That is, "i" can be treated as a variable. The simplification comes at the end, where any instances of i² can be replaced by -1.

  xy = (3 +8i)(7 -i) = 3·7 -3·i +8·7·i -8·i·i = 21 +53i -8i²

  = (21 +8) +53i . . . . replaced i² with -1, so -8i² = +8

  = 29 +53i