h=255-21t-16t^2

PLEASE HELP!!

From the test the person wants, and the sample data, we build the test hypothesis, find the test statistic,  and use this to reach a conclusion.

This is a two-sample test, thus, it is needed to understand the central limit theorem and subtraction of normal variables.

Doing this:

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Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

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

Proportion 1: Jet-ski users

86.5% out of 400, thus:

[tex]p_1 = 0.865[/tex]

[tex]s_1 = \sqrt{\frac{0.865*0.135}{400}} = 0.0171[/tex]

Proportion 2: boaters

92.8% out of 250, so:

[tex]p_2 = 0.928[/tex]

[tex]s_2 = \sqrt{\frac{0.928*0.072}{250}} = 0.0163[/tex]

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

Hypothesis:

Test the claim that the proportion of people who wear life vests while riding a jet ski is not the same as the proportion of people who wear life vests while riding in a boat.

At the null hypothesis, it is tested that the proportions are the same, that is, the subtraction is 0. So

[tex]H_0: p_1 - p_2 = 0 \rightarrow p_1 = p_2[/tex]

At the alternative hypothesis, it is tested that the proportions are different, that is, the subtraction is different of 0. So

[tex]H_1: p_1 - p_2 \neq 0 \rightarrow p_1 \neq p_2[/tex]

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

Test statistic:

The test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.

0 is tested at the null hypothesis.

This means that [tex]\mu = 0[/tex]

From the samples:

[tex]X = p_1 - p_2 = 0.865 - 0.928 = -0.063[/tex]

[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{0.0171^2 + 0.0163^2} = 0.0236[/tex]

The value of the test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{-0.063 - 0}{0.0236}[/tex]

[tex]z = -2.67[/tex]

The value of the test statistic is z = -2.67.

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

p-value of the test and decision:

The p-value of the test is the probability that the proportion differs by at at least 0.063, which is P(|z| > 2.67), given by 2 multiplied by the p-value of z = -2.67.

Looking at the z-table, z = -2.67 has a p-value of 0.0038.

2*0.0038 = 0.0076.

The p-value of the test is 0.0076 < 0.05(standard significance level), which means that there is enough evidence to conclude that the proportion of people who wear life vests while riding a jet ski is not the same as the proportion of people who wear life vests while riding in a boat.

A similar question is found at https://brainly.com/question/24250158

Answer:

pordondede donde eres?

Step-by-step explanation:

........................

Answer:

(g÷f) (x) (1.8) ³x²+⁷x+2

Step-by-step explanation:

Im glad to help you

Explanation:

Stratified sampling involves breaking a population of people into separate groups, where there isn't any overlap.

An example would be having a high school with freshmen, sophomores, juniors and seniors. A person can only belong to one group (so we can't have someone whos a freshman and a sophomore at the same time for instance). In that example, each group or strata is a different grade level.

As for this particular problem, each strata is a different ethnicity, and there are 6 strata total.

The researcher is using stratified sampling. The correct option is C.

A method of sampling from a population that can be divided into subpopulations is known as stratified sampling in statistics. When subpopulations within a larger population differ, it may be desirable to sample each subpopulation separately in statistical surveys.

Stratified sampling involves breaking a population of people into separate groups, where there isn't any overlap.

An example would be having a high school with freshmen, sophomores, juniors, and seniors. A person can only belong to one group (so we can't have someone whos a freshman and a sophomore at the same time for instance). In that example, each group or strata is a different grade level.

As for this particular problem, each stratum is different ethnicity, and there is 6 strata total.

To know more about stratified sampling follow

https://brainly.com/question/1954758

#SPJ5

Answer:

With an ageing population, dietary approaches to promote health and independence later in life are needed. In part, this can be achieved by maintaining muscle mass and strength as people age. New evidence suggests that current dietary recommendations for protein intake may be insufficient to achieve this goal and that individuals might benefit by increasing their intake and frequency of consumption of high-quality protein. However, the environmental effects of increasing animal-protein production are a concern, and alternative, more sustainable protein sources should be considered. Protein is known to be more satiating than other macronutrients, and it is unclear whether diets high in plant proteins affect the appetite of older adults as they should be recommended for individuals at risk of malnutrition. The review considers the protein needs of an ageing population (>40 years old), sustainable protein sources, appetite-related implications of diets high in plant proteins, and related areas for future research.

9514 1404 393

Answer:

  (9√3 -3π/2) ft^3 ≈ 10.88 ft^3

Step-by-step explanation:

The area of the hexagon is given by the formula ...

  A = (3/2)√3·s^2 . . . . for side length s

The area of the hexagonal face of this solid is ...

  A = (3/2)√3·(2 ft)^2 = 6√3 ft^2

__

The area of the circular hole in the hexagonal face is ...

  A = πr^2

The radius is half the diameter, so is r = (2 ft)/2 = 1 ft.

  A = π(1 ft)^2 = π ft^2

Then the area of the "solid" part of the face of the figure is ...

  A = (6√3 -π) ft^2

__

The volume is ...

  V = Bh . . . . . where B is the area of the base of the prism, and h is its height

  V = ((6√3 -π) ft^2)(3/2 ft) = (9√3 -3π/2) ft^3 ≈ 10.88 ft^3

Answer:

b is your answer hope it is helpful

Answer:

b is the correct answer

Step-by-step explanation:

the answer is b

Answer:

dont know

Step-by-step explanation:

9514 1404 393

Answer:

Step-by-step explanation:

Part A: All of the coefficients have a common factor of 3. All of the variable products have a common factor of y, so the greatest common factor of all terms is 3y. The expression can be written as ...

  (3y)(2x^2 -1x -8xy +4y)

__

Part B: The remaining factor can be factored pairwise:

  3y(x(2x -1) -4y(2x -1)) = 3y(x -4y)(2x -1)

Answer:

x = 50

Step-by-step explanation:

When two secants intersect in the interior of a circle, the angles formed are the average of the arc an angle and its vertical intercept. In this case, our angle, 73, should be the average of x and 96. We can translate this to an equation and solve:

[tex]\frac{x+96}{2} = 73[/tex]

x + 96 = 146

x = 50

Answer:

-2/3

Step-by-step explanation:

We can use the slope formula

m = ( y2-y1)/(x2-x1)

   = ( 1-3)/(-2 - -5)

   = (1-3)/(-2+5)

    = -2/3

Answer:

Step-by-step explanation:

(z)° + (3z + 1)° = 360° - ( 54° + 204° )

z + 3z + 1 = 360 - 258

4z = 101

z = 25.25

Step-by-step explanation:

the box is

9 in × 3.5 in × 4.5 in = 141.75 in³

each block is

0.5 in × 0.5 in × 0.5 in = 0.125 in³ (1/8 in³)

so, we can fit

141.75 / 0.125 = 1134

blocks into the box.

and they fit neatly, as the dimensions of the box and the cubes allow a tight packing without any empty left over space in the box.

Answer:

Yeah, x varies directly with (6 - y)

Step-by-step explanation:

[tex]x = 6 - y \\ x = k(6 - y) \\ x \: \alpha \: (6 - y)[/tex]

Answer:

2016

Step-by-step explanation:

using USA dollars:

$42000 x .072 (7.2%) = 3024 total commission

3024 x 2/3 = 2016 brokers amount

Answer:

I don't know because I don't understand what you mean

Answer:

Step-by-step explanation:

It’s a cube with edge length of 12 cm.

The cube has six faces, and the are ma if each face is 144 cm²

Total surface area = 6×144 = 864 cm²

Answer:

cube    864

Step-by-step explanation:

Step-by-step explanation:

her it Go i think it is helpful for u

Answer:

4^15

Step-by-step explanation:

We know a^b^c = a^(b*c)

4^3^5

4^(3*5)

4^15

Answer:

d. the current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval.

Step-by-step explanation:

Mean was of 8 hours, test if it has changed:

At the null hypothesis, we test if it has not changed, that is, the mean is still of 8, so:

[tex]H_0: \mu = 8[/tex]

At the alternative hypothesis, we test if it has changed, that is, the mean is different of 8, so:

[tex]H_1: \mu \neq 8[/tex]

Using a 95% confidence interval of (7.7, 9.3), our conclusion is that:

8 is part of the confidence interval, which means that the study does not provide evidence that the mean has changed, and the correct answer is given by option d.

Answer:

0.16777216

Step-by-step explanation:

(. 8)^8=0.16777216

Start with a volume of a cuboid,

[tex]V=abc=3\cdot2\cdot3=18\mathrm{cm^3}[/tex]

The side of the cube we need equals to the LCM of the cubiod's sides,

[tex]\mathrm{LCM}(a,b,c)=\mathrm{LCM}(3,2,3)=6[/tex]

Now compute the volume of such cube,

[tex]V=\mathrm{LCM}(a,b,c)^3=6^3=216\mathrm{cm^3}[/tex]

Divide the volumes to get how many cubiods are in such cube,

[tex]\dfrac{V_{\mathrm{cube}}}{V_{\mathrm{cubiod}}}=\dfrac{216}{18}=\boxed{12}[/tex]

Hope this helps :)

Answer:

Hi,

Answer: 12

Step-by-step explanation:

lcm(3,2,3)=6

Volume of a cuboid=3*2*3=18 (cm³)

Volume of the cube=6³=216 (cm³)

Number of cuboids=216/18=12.

9514 1404 393

Answer:

  e = 225

Step-by-step explanation:

To eliminate the coefficient of e, multiply both sides of the equation by its reciprocal. The reciprocal of -1/75 is -75.

  (-75)(-3) = (-75)(-e/75)

  225 = e

Answer:

Right angled and isosceles

Answer:

See Below.

Step-by-step explanation:

We have the equation:

[tex]\displaystyle y = \left(3e^{2x}-4x+1\right)^{{}^1\! / \! {}_2}[/tex]

And we want to show that:

[tex]\displaystyle y \frac{d^2y }{dx^2} + \left(\frac{dy}{dx}\right) ^2 = 6e^{2x}[/tex]

Instead of differentiating directly, we can first square both sides:

[tex]\displaystyle y^2 = 3e^{2x} -4x + 1[/tex]

We can find the first derivative through implicit differentiation:

[tex]\displaystyle 2y \frac{dy}{dx} = 6e^{2x} -4[/tex]

Hence:

[tex]\displaystyle \frac{dy}{dx} = \frac{3e^{2x} -2}{y}[/tex]

And we can find the second derivative by using the quotient rule:

[tex]\displaystyle \begin{aligned}\frac{d^2y}{dx^2} & = \frac{(3e^{2x}-2)'(y)-(3e^{2x}-2)(y)'}{(y)^2}\\ \\ &= \frac{6ye^{2x}-\left(3e^{2x}-2\right)\left(\dfrac{dy}{dx}\right)}{y^2} \\ \\ &=\frac{6ye^{2x} -\left(3e^{2x} -2\right)\left(\dfrac{3e^{2x}-2}{y}\right)}{y^2}\\ \\ &=\frac{6y^2e^{2x}-\left(3e^{2x}-2\right)^2}{y^3}\end{aligned}[/tex]

Substitute:

[tex]\displaystyle y\left(\frac{6y^2e^{2x}-\left(3e^{2x}-2\right)^2}{y^3}\right) + \left(\frac{3e^{2x}-2}{y}\right)^2 =6e^{2x}[/tex]

Simplify:

[tex]\displaystyle \frac{6y^2e^{2x}- \left(3e^{2x} -2\right)^2}{y^2} + \frac{\left(3e^{2x}-2\right)^2}{y^2}= 6e^{2x}[/tex]

Combine fractions:

[tex]\displaystyle \frac{\left(6y^2e^{2x}-\left(3e^{2x} - 2\right)^2\right) +\left(\left(3e^{2x}-2\right)^2\right)}{y^2} = 6e^{2x}[/tex]

Simplify:

[tex]\displaystyle \frac{6y^2e^{2x}}{y^2} = 6e^{2x}[/tex]

Simplify:

[tex]6e^{2x} \stackrel{\checkmark}{=} 6e^{2x}[/tex]

Q.E.D.

Answer:

$16

Step-by-step explanation:

Both lines start at 0 and at 30 mins it is $6. It displays a ratio so that means every 10 mins they earn $2

Answer:

2/3 scoop

Step-by-step explanation:

1/6 + 1/6 = 2/6 = 1/3

Answer: 2/3 scoop

Answer:

A

Step-by-step explanation:

The degree of the Polynomial is 3