According to a recent survey, women chat on their mobile phones more than do men (CNN.com, August 25, 2010). To determine if the same patterns also exist in colleges, Irina takes a random sample of 40 male students and 40 female students in her college. She finds that female students chatted for a sample average of 820 minutes per month, with a sample standard deviation of 160 minutes. Male students, on the other hand, chatted for a sample average of 760 minutes per month, with a sample standard deviation of 240 minutes. It is not reasonable to assume equal population variances. Test the hypothesis whether women chat on their phones more than men at the 5% significance level.
A report on a study in which each of 6 workers was provided with both a conventional shovel and a shovel whose blade was perforated with small holes.
Worker: 1 2 3 4 5 6
Conventional: .0011 .0014 .0018 .0022 .0017 .0016
Perforated: .0011 .0010 .0019 .0013 .0011 .0015
Do these data provide convincing evidence that the mean energy expenditure using the conventional shovel exceeds that using the perforated shovel? Test the relevant hypotheses using a significance level of 0.05?

Answer:

5. [tex]a ( x + y^{2} + z )[/tex]

6. [tex]2a ( x + y + z)[/tex]

7. [tex]4 ( x +4y)[/tex]

8. [tex]-5 ( x + y )[/tex]

9. [tex]7a ( a + b)[/tex]

10. [tex]-2 ( x + 2y + 3z)[/tex]

11. [tex]bx ( a + y)[/tex]

12. [tex]-x (x^{2} + x + 1)[/tex]

this took long but i hope the answers are correct :)

Answer:

8√2

Step-by-step explanation:

this one is a right triangle so both side are equal since the angle is 45 degrees

The density function fy(t) of the random variable Y, where Y = 2x - 2, can be determined by transforming the density function of the random variable X using the given relationship.

To find fy(t), we first need to find the inverse relationship between X and Y. From Y = 2x - 2, we can solve for x:

x = (Y + 2) / 2

Next, we substitute this expression for x in the density function of X, fX(x):

fX(x) = c(3x² + 4)

Substituting (Y + 2) / 2 for x, we have:

fX((Y + 2) / 2) = c[3((Y + 2) / 2)² + 4]

Simplifying the expression:

fX((Y + 2) / 2) = c(3/4)(Y² + 4Y + 4) + 4c

Expanding and simplifying further:

fX((Y + 2) / 2) = (3/4)cY² + 3cY + (3/4)c + 4c

Combining like terms:

fX((Y + 2) / 2) = (3/4)cY² + (12c + 3c)Y + (3/4)c + 4c

Now, we can see that fy(t), the density function of Y, is a quadratic function of Y. The specific coefficients and constants will depend on the values of c.

It is important to note that we need to specify the region where fy(t) is defined. Since fy(t) is derived from fX(x), we need to ensure that the transformation (Y = 2x - 2) is valid for the range of x values where fX(x) is defined.

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Cantor's Theorem states that the cardinality of a set A is strictly less than the cardinality of its power set P(A), for every set A. In other words, there is no bijection between A and P(A).

The proof of Cantor's Theorem relies on a diagonalization argument. Suppose there is a bijection f between A and P(A). We can use f to construct a subset B of A that is not in the image of f.

To do this, we define B as follows: for each element x in A, if x is not in the set f(x), then we add x to B. In other words, B contains all elements of A that are not in their corresponding set in P(A) under f.

Now, we show that B is not in the image of f. Suppose that there exists some element y in A such that f(y) = B. Then, we have two cases: either y is in B or y is not in B.

If y is in B, then y is not in f(y), since y was added to B precisely because it is not in its corresponding set in P(A) under f. But this contradicts the assumption that f(y) = B.

If y is not in B, then y is in f(y), since y is not in B precisely because it is in its corresponding set in P(A) under f. But this also contradicts the assumption that f(y) = B.

Therefore, we have shown that B is not in the image of f, which contradicts the assumption that f is a bijection between A and P(A). Thus, there can be no such bijection, and Cantor's Theorem follows.

The consequence of Cantor's Theorem is that there are different sizes of infinity, which has profound implications for mathematics and philosophy. It shows that there are sets that are "larger" than others, and that there is no "largest" infinity. This has led to the development of set theory as a foundational branch of mathematics, and has influenced debates about the nature of infinity in philosophy.

Answer:

I THINK C I’m not totally sure because it has an end point visible

Step-by-step explanation:

Answer:

x = 112°

Step-by-step explanation:

To find the value of x, you need to understand the properties of vertical and supplementary angles and know that the sum of angles inside a triangle is 180°.

Answer:

2 friends have more than 5 cards

Step-by-step explanation:

Incomplete question;

I will answer this question with the attached dot plot

The horizontal axis represents the friends, the vertical represents the number of baseball trading cards and the dots represent the frequency

So, we have:

[tex]Friend\ 1 = 2[/tex]

[tex]Friend\ 2 = 3[/tex]

[tex]Friend\ 3 = 7[/tex]

[tex]Friend\ 4 = 4[/tex]

[tex]Friend\ 5 = 2[/tex]

[tex]Friend\ 6 = 6[/tex]

[tex]Friend\ 7 = 2[/tex]

[tex]Friend\ 8 = 5[/tex]

[tex]Friend\ 9 = 1[/tex]

[tex]Friend\ 0 = 0[/tex]

The friends that has more than 5 are:

[tex]Friend\ 3 = 7[/tex]

[tex]Friend\ 6 = 6[/tex]

Hence, 2 friends have more than 5 cards

Answer:

1 block is required in the process to balance the scale

Step-by-step explanation:

In order to get the process that will balance the scale, we need to solve the given expression for x as shown;

3x + 1 = x+ 3

Subtract x from both sides

3x+1-x = x+3 - x

3x - x + 1 = 3

2x + 1 = 3

Subtract 1 from both sides

2x + 1 - 1 = 3 -1

2x = 2

Divide both sides by 2

2x/2 = 2/2

x = 1

Hence 1 block is required in the process to balance the scale

Answer:

The odds against  a person selected at random from these 39 people testing negative on the test is 92.31%.

Step-by-step explanation:

In the group of 39 randomly selected people:

# of people tested negative: 36

36 / 39 = 92.31%

The average sum of differences of a series of numerical data from their mean is zero (option a).

This property holds true for any data set when calculating the mean deviation (also known as the average deviation) from the mean. The mean deviation is calculated by taking the absolute difference between each data point and the mean, summing them up, and dividing by the number of data points.

However, it's important to note that this property does not hold true when using squared differences, which is used in the calculation of variance and standard deviation. In those cases, the average sum of squared differences from the mean would give the variance (option c) or the squared standard deviation (option e).

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Given x is the score in the distribution. The interval of scores containing within one standard deviation from the mean is a < x < b. The solution for a and b are; a = x - SD and b = x + SD.

Let's see how we can solve these problems using the standard deviation and distribution.

36. To solve for a:

One standard deviation from the mean in a normal distribution includes about 68 percent of the scores.

Therefore, we know that:

P(mean - SD < x < mean + SD) = 68%. Where, SD = standard deviation of the distribution.

Therefore, to find a, we need to subtract SD from the mean.

So, a = mean - SD.

Distribution:

a < x < b

P(mean - SD < x < mean + SD) = 68%

Mean is x in this case; so:

P(x - SD < x < x + SD) = 68%

Now, solve for a by subtracting SD from x:

x - SD = a = x - SD

37). To solve for b.

From the previous problem,

we have: P(x - SD < x < x + SD) = 68%

To find b, we need to add SD to x

So, b = x + SD

Substitute the values of SD and x to get the value of b.

Distribution: a < x < b

P(mean - SD < x < mean + SD) = 68%

P(x - SD < x < x + SD) = 68%

So,

a = x - SD and b = x + SD.

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36. The value of a is µ - σ for the interval of scores containing within one standard deviation from the mean is a < x < b.

37. The value of b is µ + σ for the interval of scores containing within one standard deviation from the mean is a < x < b.

Explanation:

Given that x is the score in the distribution. The interval of scores containing within one standard deviation from the mean is a < x < b. We need to find the values of a and b.

Formula used:

µ ± σ,

where µ = mean

σ = standard deviation.

Using this formula we can write:

               µ - σ < x < µ + σ

36.

Given that x is the score in the distribution.

The interval of scores containing within one standard deviation from the mean is a < x < b.

Substitute the above formula in the given expression: µ - σ < x

a = µ - σ

µ - σ  = a + σ

a = µ - σ

Thus, the value of a is µ - σ.

37.

Given that x is the score in the distribution.

The interval of scores containing within one standard deviation from the mean is a < x < b.

solve for b.

Substitute the above formula in the given expression:

xa < µ + σ

b = µ + σ

µ + σ = b - σ

b = µ + σ

Thus, the value of b is µ + σ.

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The value of y corresponding to x₀ + 0.2 is approximately 0.6701  and the value of y corresponding to x₀ + 0.4 is approximately 0.5650 using Heun's method .

The differential equation using Heun's method, we will approximate the values of y at x₀ + 0.2 and x₀ + 0.4 based on the initial condition y(0) = 1.

Heun's method involves using the slope at two points to estimate the next point. The algorithm for Heun's method is as follows:

Given the initial condition y(x₀) = y₀, let h be the step size.

Set x = x₀ and y = y₀.

Compute k₁ = f(x, y) = -xy + 2(x² × eˣ - y²), where f(x, y) is the given differential equation.

Compute k₂ = f(x + h, y + hk₁).

Update y = y + (h/2) × (k₁ + k₂).

Update x = x + h.

Using the given initial condition y(0) = 1, we'll apply Heun's method to find the values of y at x₀ + 0.2 and x₀ + 0.4.

Initial condition

x₀ = 0

y₀ = 1

Step size

h = 0.2 (given)

Iterating through the steps until we reach x = 0.4:

x = 0, y = 1

k₁ = -0 × 1 + 2(0² × e⁰ - 1²) = -1

k₂ = f(0.2, 1 + 0.2×(-1)) = f(0.2, 0.8) = -0.405664

y = 1 + (0.2/2) × (-1 + (-0.405664)) = 0.7978688

x = 0.2, y = 0.7978688

k₁ = -0.2 × 0.7978688 + 2(0.2² × [tex]e^{0.2}[/tex] - 0.7978688²)

= -0.1777845

k₂ = f(0.4, 0.7978688 + 0.2×(-0.1777845))

= f(0.4, 0.7633118)

= -0.2922767

y = 0.7978688 + (0.2/2) × (-0.1777845 + (-0.2922767))

= 0.6701055

x = 0.4, y = 0.6701055

k₁ = -0.4 × 0.6701055 + 2(0.4² × [tex]e^{0.4}[/tex] - 0.6701055²)

= -0.1027563

k₂ = f(0.6, 0.6701055 + 0.2×(-0.1027563))

= f(0.6, 0.6495543)

= -0.2228019

y = 0.6701055 + (0.2/2) × (-0.1027563 + (-0.2228019))

= 0.5649933

Therefore, the value of y corresponding to x₀ + 0.2 is approximately 0.6701 (correct to four decimal places) and the value of y corresponding to x₀ + 0.4 is approximately 0.5650 (correct to four decimal places).

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Answer:

80%

Step-by-step explanation:

You started of with 5/5 once one slice was eat it became 4/5

you must then convert 4/5 into a percent

To convert a fraction to a percent, divide the numerator by the denominator. Then multiply the decimal by 100.

so 4 divided by 5 =0.8

0.8 x 100= 80

80%

[tex]\sinh'(x) = \cosh(x)$.[/tex]

Hence, we have shown that [tex]\cosh'(x) = \sinh(x)$ and $\sinh'(x) = \cosh(x)$[/tex] using the rules for differentiating [tex]e^x$.[/tex]

What are Hyperbolic Functions?

Hyperbolic functions are a set of mathematical functions that are analogs of the trigonometric functions. While trigonometric functions are defined based on the unit circle, hyperbolic functions are defined using the hyperbola.

To show that [tex]\cosh'(x) = \sinh(x)$ and $\sinh'(x) = \cosh(x)$[/tex] using the rules for differentiating [tex]e^x$:[/tex]

[tex]\textbf{1. Derivative of $\cosh(x)$:}[/tex]

Starting with the definition of [tex]\cosh(x)$:[/tex]

[tex]\[\cosh(x) = \frac{1}{2}(e^x + e^{-x})\][/tex]

Taking the derivative with respect to x using the chain rule and the derivative of [tex]e^x$:[/tex]

[tex]\cosh'(x) &= \frac{1}{2}\left(\frac{d}{dx}(e^x) + \frac{d}{dx}(e^{-x})\right) \\\\&= \frac{1}{2}(e^x - e^{-x}) \\\\&= \sinh(x)[/tex]

Therefore, [tex]\cosh'(x) = \sinh(x)$.[/tex]

[tex]\textbf{2. Derivative of $\sinh(x)$:}[/tex]

Starting with the definition of [tex]\sinh(x)$:[/tex]

[tex]\[\sinh(x) = \frac{1}{2}(e^x - e^{-x})\][/tex]

Taking the derivative with respect to x using the chain rule and the derivative of [tex]$e^x$[/tex]:

[tex]\sinh'(x) &= \frac{1}{2}\left(\frac{d}{dx}(e^x) - \frac{d}{dx}(e^{-x})\right) \\\\&= \frac{1}{2}(e^x + e^{-x}) \\\\&= \cosh(x)[/tex]

Therefore, [tex]\sinh'(x) = \cosh(x)$.[/tex]

Hence, we have shown that [tex]\cosh'(x) = \sinh(x)$ and $\sinh'(x) = \cosh(x)$[/tex] using the rules for differentiating [tex]e^x$.[/tex]

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Answer:

See attachment

Step-by-step explanation:

Given

See attachment for complete question

Required

Determine the new model

From the question;

Furaha's model is: 6 by 4

Rahma's model is: 7 by 4

When Furaha's rectangle is pushed next to Rahma's, the new model becomes: (6 + 7) by 4

i.e. 13 by 4

See attachment 2

Answer: y = 2/9x + 8 and -2y = 9x + 8

Step-by-step explanation: Hope this help :D

Parallel lines have the same slope so y = 2/9x + 8 and 9y = 2x -18 will be parallel to the line y = 2/9x - 7 so option (B) and (D) will be correct.

Two lines in the same plane that are equally spaced apart and never cross each other are said two lines in the same plane that are equally spaced apart and never cross each other to be parallel lines.

Parallel lines are those lines in which slopes are the same and the distance between them remains constant.

The equation of a linear line is given by

y = mx  + x where m is slope

So,

y = 2/9x - 7 have slope as 2/9

Now since parallel lines have the slope same so all lines whose slope matches with 2/9 will be parallel to this.

So,

y = 2/9x + 8 has slope of 2/9

9y = 2x -18 ⇒ y = 2/9 x - 2 has slope of 2/9

Hence "y = 2/9x + 8 and 9y = 2x -18 will be parallel to the line y = 2/9x - 7"

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Answer:

8x+3y-2x-4y-6x​ = -y

Step-by-step explanation:

8x+3y-2x-4y-6x​ = ?

combine like terms:

(8x - 2x - 6x) + (3y - 4y) = ?

The x total is 0 and the y total is -1y

Answer:

-1y

Step-by-step explanation:

8x-2x-6x=0

3y-4y=-1y

That means the solution I think is -1y.

I say this because the X gets completely cancelled, and then the only thing left is -1y. If the X still had a number in front of it, it would then be like (This Is An Example: 2x = -1y) That's what it would look like if the X wasn't completely cancelled out. Have a good day. And if you see any fault in my answer please let me know so I can get better with problems like these. Thanks.

f(x)=-4x-5

x=4, 1, 3, 11

f(4)=-4(4)-5=-16-5=-21

f(1)=-4-5=-9

f(3)=-12-5=-17

f(11)=-44-5=-49

-21, -9, -17, -49

The solution to the given initial-value problem is a power series given by y(x) = 1 - 2x^3 + 3x^4 + O(x^5).  As x increases, higher powers of x become significant, and the series must be truncated at an appropriate order to maintain accuracy .

y(x) = a_0 + a_1x + a_2x^2 + a_3x^3 + a_4x^4 + ..., where a_0, a_1, a_2, ... are constants to be determined. We then differentiate the series term-by-term to find the derivatives y' and y''. Differentiating y(x), we have

y' = a_1 + 2a_2x + 3a_3x^2 + 4a_4x^3 + ..., and differentiating once more, we find y'' = 2a_2 + 6a_3x + 12a_4x^2 + ...Substituting these expressions into the given differential equation, we have:

(x + 3)(2a_2 + 6a_3x + 12a_4x^2 + ...) + 2(a_0 + a_1x + a_2x^2 + a_3x^3 + a_4x^4 + ...) = 0

Given the initial conditions y(0) = 1 and y'(0) = 0, we can use these conditions to find the values of a_0 and a_1. Plugging in x = 0 into the power series, we have a_0 = 1. Differentiating y(x) and evaluating at x = 0, we get a_1 = 0.Therefore, the power series solution is y(x) = 1 + a_2x^2 + a_3x^3 + a_4x^4 + ..., where a_2, a_3, a_4, ... are yet to be determined.

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Answer:

Inequality Form:

h > 6

Interval Notation:

( 6 , ∞ )

Step-by-step explanation:

Isolate the variable by dividing each side by factors that don't contain the variable.

The true statement about the polynomial function is (d) 0 relative minimum

From the question, we have the following parameters that can be used in our computation:

f(x) = x³ + 2x² - 1

Differentiate and set the function o 0

So, we have

3x² + 4x = 0

Factor the expression

So, we have

x(3x + 4) = 0

Next, we have

x = 0 or x = -4/3

So, we have

f(0) = (0)³ + 2(0)² - 1 = -1

f(-4/3) = (-4/3)³ + 2(-4/3)² - 1 = 0.2

This means that it has a relative minimum at x = 0

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The value of the correlation coefficient is represented by the symbol "r." It is a statistical measure that determines the degree of correlation or association between two variables.

There are various methods of calculating r, but the most common one is the Pearson correlation coefficient. To calculate the Pearson correlation coefficient, follow these steps:

Step 1: Collect the data for the two variables you want to determine the correlation for. The data should be continuous and normally distributed.

Step 2: Calculate the mean of both variables.

Step 3: Calculate the standard deviation of both variables.

Step 4: Calculate the covariance of the two variables using the formula below: `Cov(X, Y) = Σ [(Xi - Xmean) * (Yi - Ymean)] / (n-1)

`Step 5: Calculate the correlation coefficient using the formula below: `r = Cov(X, Y) / (SD(X) * SD(Y))` where r is the correlation coefficient, Cov is the covariance, SD is the standard deviation, X is the first variable, Y is the second variable, Xi and Yi are the individual values of X and Y, X mean and Y mean are the means of X and Y, and n is the number of observations. The resulting value of r ranges from -1 to +1. A value of -1 indicates a perfect negative correlation, a value of 0 indicates no correlation and a value of +1 indicates a perfect positive correlation.

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9514 1404 393

Answer:

  6 3/10 pounds

Step-by-step explanation:

The weight change will be found by multiplying the rate of change by the time.

  ∆w = (-1.8 lb/h)(3.5 h) = -6.3 lb

The total change in weight after 3 1/2 hours is 6 3/10 = 6.3 pounds.

[tex]\huge{\mathbb{\tt { PROBLEM:}}}[/tex]

Help What is 103883+293883=?

[tex]\huge{\mathbb{\tt { ANSWER:}}}[/tex]

[tex]{\boxed{\boxed{\tt { SOLUTION:}}}}[/tex]

[tex] \: \: \: 103883 \\ \frac{+293883}{ \: \: \: \: 397766} [/tex]

[tex]\huge{\mathbb{\tt { WHAT \: IS \: ADDITION \: ?}}}[/tex]

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Answer:

I think it's B

Step-by-step explanation:

x = -2

2 + x > -8

2 + -2 > -8

0 > -8

Answer:

The answer is B

Step-by-step explanation:

Divide 48 by 3 which gives you the total amount for one bracelet then you have to multiply the amount by 9 and 13 and then find your answer in the letters.

The proportion relationship is as follows;

number of bracelet         total cost($)

                3                           48

                9                            144

               13                           208

Proportional relationship is one in which two quantities vary directly with each other.

Therefore, we can establish a proportional relationship between the number of bracelets and it cost.

Hence,

let

x = number of bracelet

y = cost of the bracelets

Therefore,

y = kx

where

k = constant of proportionality

48 = 3k

k = 48 / 3

k = 16

Let's find the cost for 9 or 13 bracelet

y = 12x

y = 16(9) = 144

y = 16(13) = 208

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