20 points!
Please help.

Answer:

16

Step-by-step explanation:

It’s a ratio.

x/12=21/28

21x=12*28

21x=336

x=336/21

x=16

Answer:

Step-by-step explanation:

Given that:

mean μ = 70

sample size = 25

sample mean = 73

standard deviation = 7

level of significance = 0.10

The null hypothesis and the alternative hypothesis can be computed as follows:

[tex]\mathtt{H_o : \mu = 70} \\ \\ \mathtt{H_1 : \mu > 70 }[/tex]

The z score for this statistics can be calculated by using the formula:

[tex]z = \dfrac{X- \mu}{\dfrac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \dfrac{73- 70}{\dfrac{7}{\sqrt{25}}}[/tex]

[tex]z = \dfrac{3}{\dfrac{7}{5}}[/tex]

[tex]z = \dfrac{3 \times 5}{{7}{}}[/tex]

z = 2.143

At level of significance of 0.10

degree of freedom = n -1

degree of freedom = 25 - 1

degree of freedom = 24

The p - value from the z score at   level of significance of 0.10 and degree of freedom of 24 is:

P - value = 1 - (Z < 2.143)

P - value =  1 - 0.9839

P - value =  0.0161

Decision Rule: since P value is lesser than the level of significance, we reject the null hypothesis.

Conclusion: We conclude that energy drink consumption increases heart rate.

Answer:

A) distribution of x2 = ( 0.4167 0.25 0.3333 )

B) steady state distribution = [tex]\pi a \frac{4}{9} , \pi b \frac{2}{9} , \pi c \frac{3}{9}[/tex]

Step-by-step explanation:

Hello attached is the detailed solution for problems A and B

A) distribution states for A ,B, C:

Po = ( 1/3, 1/3, 1/3 )  we have to find the distribution of x2 as attached below

after solving the distribution

x 2 = ( 0.4167, 0.25, 0.3333 )

B ) finding the steady state distribution solving

[tex]\pi p = \pi[/tex]

below is the detailed solution and answers

Answer:

36

step by step

given length=6

so area of square is given by s2 i.e 6^2

=6×6

=36 (Ans)

[tex]a=\dfrac{2}{3}\\r=\dfrac{1}{2}[/tex]

The sum exists if [tex]|r|<1[/tex]

[tex]\left|\dfrac{1}{2}\right|<1[/tex] therefore the sum exists

[tex]\displaystyle\\\sum_{k=0}^{\infty}ar^k=\dfrac{a}{1-r}[/tex]

[tex]\dfrac{2}{3}+\dfrac{1}{3}+\dfrac{1}{6}+\ldots=\dfrac{\dfrac{2}{3}}{1-\dfrac{1}{2}}=\dfrac{\dfrac{2}{3}}{\dfrac{1}{2}}=\dfrac{2}{3}\cdot 2=\dfrac{4}{3}[/tex]

Answer:

34 grams

Step-by-step explanation:

If the remaining sample has 30.26 grams of radioactive substance, and 11% of it decayed, that means that 30.26 grams is 89% of the original. Let the original be x.

30.26=0.89x

Multiply both by one hundred

3026=89x

Divide both by 89

34=x

x=original, so the original was 34 grams.

Answer:

Find answer below

Step-by-step explanation:

f(x)=2x-6

Domain of 2x-6: {solution:-∞<x<∞, interval notation: -∞, ∞}

Range of 2x-6: {solution:-∞<f(x)<∞, interval notation: -∞, ∞}

Parity of 2x-6: Neither even nor odd

Axis interception points of 2x-6: x intercepts : (3, 0) y intercepts (0, -6)

inverse of 2x-6: x/2+6/2

slope of 2x-6: m=2

Plotting : y=2x-6

Answer/Step-by-step explanation:

The idea to use in solving this problem using the model, is to express the number of shaded boxes in fraction form.

Thus, the blue red shaded boxes has 34 boxes shaded out of 100 boxes. This represents [tex] \frac{34}{100} [/tex]. This will give us 0.34.

The other shaded boxes represents [tex] \frac{49}{100} = 0.49 [/tex].

Using the model, we can solve 0.34 + 0.49.

Add both fractions together.

[tex] \frac{34}{100} + \frac{49}{100} = \frac{34+49}{100} [/tex]

[tex] \frac{83}{100} = 0.83 [/tex]

Answer: 2.40

Step-by-step explanation:

Given: The prices of 4 cars with similar characteristics that sold at a recent auction (in thousands of dollars): 6.6, 5, 10.7, 7.3.

Let x: 6.6, 5, 10.7, 7.3.

n= 4

Mean : [tex]\overline{x}=\dfrac{\sum x}{n}[/tex]

[tex]\Rightarrow\ \overline{x}=\dfrac{6.6+5+10.7+7.3}{4}\\\\=\dfrac{29.6}{4}\\\\=7.4[/tex]

Now , standard deviation = [tex]\sqrt{\dfrac{\sum(x-\overline{x})^2}{n-1}}[/tex]

[tex]=\sqrt{\dfrac{(6.6-7.4)^2+( 5-7.4)^2+( 10.7-7.4)^2+( 7.3-7.4)^2}{4-1}}\\\\=\sqrt{\dfrac{0.64+5.76+10.89+0.01}{3}}\\\\=\sqrt{\dfrac{17.3}{3}}\approx2.40[/tex]

Hence, the standard deviation of the sample of selling prices = 2.40

Answer:

z(s) is in the acceptance region. We accept H₀  we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine

Step-by-step explanation:

We must evaluate the differences of the means of the two machines, to do so, we will assume a CI  of 95%, and as the interest is to find out if the new machine has better performance ( machine has a bigger efficiency or the new machine produces more units per unit of time than the old one) the test will be a one tail-test (to the left).

New machine

Sample mean                  x₁ =    25

Sample variance               s₁  = 27

Sample size                       n₁  = 45

Old machine

Sample mean                    x₂ =  23  

Sample variance               s₂  = 7,56

Sample size                       n₂  = 36

Test Hypothesis:

Null hypothesis                         H₀             x₂  -  x₁  = d = 0

Alternative hypothesis             Hₐ            x₂  -  x₁  <  0

CI = 90 %  ⇒  α =  10 %     α = 0,1      z(c) = - 1,28

To calculate z(s)

z(s)  =  ( x₂  -  x₁ ) / √s₁² / n₁  +  s₂² / n₂

s₁  = 27     ⇒    s₁²  =  729

n₁  = 45    ⇒   s₁² / n₁    = 16,2

s₂  = 7,56   ⇒    s₂²  = 57,15

n₂  = 36     ⇒    s₂² / n₂  =  1,5876

√s₁² / n₁  +  s₂² / n₂  =  √ 16,2  + 1.5876    = 4,2175

z(s) = (23 - 25 )/4,2175

z(s)  =  - 0,4742

Comparing z(s) and  z(c)

|z(s)| < | z(c)|  

z(s) is in the acceptance region. We accept H₀  we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine

The very hight dispersion of values s₁ = 27 is evidence of frecuent values quite far from the mean

Answer:

Kelvin did not skied without falling more than twice as long as anyone else in his family.

Step-by-step explanation:

The inequality representing the event where Kelvin skied without falling more than twice as long as anyone else in his family is:

[tex]2f<223[/tex]

Here 223 is the time for Kelvin.

[tex]2f<223[/tex]

[tex]2\times 55=110<223[/tex]

Kelvin skied without falling more than twice as long as Lori.

[tex]2f<223[/tex]

[tex]2\times 265=530>223[/tex]

Kelvin skied without falling less than twice as long as Vanessa.

[tex]2f<223[/tex]

[tex]2\times 172=344>223[/tex]

Kelvin skied without falling less than twice as long as Devon.

[tex]2f<223[/tex]

[tex]2\times 112=224>223[/tex]

Kelvin skied without falling less than twice as long as Celia.

[tex]2f<223[/tex]

[tex]2\times 356=712>223[/tex]

Kelvin skied without falling less than twice as long as Arnold.

Thus, Kelvin did not skied without falling more than twice as long as anyone else in his family.

Answer:

Yes, Kevin skied 2x as long as Lori.

Step-by-step explanation:

Kevin's time was 223 seconds; Lori's time was 110 seconds.

110^2 = 220 or 110 multiplied by 2 equals 220 or 110 x 2 = 220 or

110 * 2 = 220

Thus, Kevin indeed, skied twice as long as Lori.

Answer:  11 down and 9 right

Step-by-step explanation:

Slope IS rise over run where the top number of the fraction (numerator) determines the vertical distance --> positive is up, negative is down

and the bottom number of the fraction (denominator) determines the horizontal distance --> positive is right, negative is left.

Given slope = -11/9

the numerator is -11 so the "rise" is  DOWN 11 units

the denominator is 9 so the "run" is RIGHT 9 units

Answer:

Question 18: B. 104

Question 19: [tex] x = \frac{3}{2} [/tex]

Step-by-step Explanation:

Question 18:

Step 1: express the inverse relationship with an equation

[tex] y = \frac{k}{x^2} [/tex] ,

where k is constant

y = 26 when x = 4,

Constant, k, = [tex] y*x^2 = k [/tex]

[tex] k = 26*4^2 = 416 [/tex]

The equation would be [tex] y*x^2 = 416 [/tex]

Step 2: use the equation to find y when X = 2.

[tex] y*x^2 = 416 [/tex]

[tex] y*2^2 = 416 [/tex]

[tex] y*4 = 416 [/tex]

Divide both sides by 4

[tex] \frac{y*4}{4} = \frac{416}{4} [/tex]

[tex] y = 104 [/tex]

Question 19:

[tex] \frac{x}{3} = \frac{x + 2}{7} [/tex]

Cross multiply

[tex] x(7) = 3(x + 2) [/tex]

[tex] 7x = 3x + 6 [/tex]

Subtract 3x from both sides

[tex] 7x - 3x = 3x + 6 - 3x [/tex]

[tex] 4x = 6 [/tex]

Divide both sides by 4

[tex] \frac{4x}{4} = \frac{6}{4} [/tex]

[tex] x = \frac{3}{2} [/tex]

Answer: D.) 52

Explanation: I guessed and got it right lol

Answer:

D. the bottom one is the answer, because hyperbola is two curves that curve infinitely

Answer:

Mean: 169.4

Median: 171

Mode: 181

Step-by-step explanation:

I first sorted the numbers by value, least to greatest.

145 147 153 153 167 170 170 172 181 181 181 182 185 185

We can see that 181 occurs the most, 3 times, so it's the mode.

The median of this set will be the middle number(s).

When we take away 6 numbers from both sides we are left with 170 and 172, and the mean of these two numbers is 171. So the median is 171.

We can add all the numbers and divide by 14 to get the mean.

[tex]147+153+170+172+185+181+182+185+181+170+181+167+153+145=2372\\\\2372\div14\approx169.4[/tex]

Hope this helped!

Complete Question

Two samples from the same population both have M = 84 and s2 = 20, but one sample has n = 10 and the other has n = 20 scores. Both samples are used to evaluate a hypothesis stating that μ = 80 and to compute Cohen’s d. How will the outcomes for the two samples compare?

a.

The larger sample is more likely to reject the hypothesis and will produce a larger value for Cohen’s d.

b.

The larger sample is more likely to reject the hypothesis, but the two samples will have the same value for Cohen’s d.

c.

The larger sample is less likely to reject the hypothesis and will produce a larger value for Cohen’s d.

d.

The larger sample is less likely to reject the hypothesis, but the two samples will have the same value for Cohen’s d.

Answer:

The Cohen's d value is  [tex]d = 0.895[/tex]

The  correct option is b

Step-by-step explanation:

From the question we are told that

   The  sample mean of  each population is  [tex]M = 84[/tex]

    The  variance of each  population is  [tex]s^2 = 20[/tex]

    The  first sample size is  [tex]n_1 = 10[/tex]

    The  second  sample size is  [tex]n_2 = 20[/tex]

The  null hypothesis is  [tex]H_o : \mu = 80[/tex]

   Generally the standard deviation is mathematically evaluated as

            [tex]s = \sqrt{20 }[/tex]

=>         [tex]s = 4.47[/tex]

  The first test statistics is evaluated as

            [tex]t_1 = \frac{M - \mu }{ \frac{\sigma }{ \sqrt{n_1} } }[/tex]

    =>    [tex]t_1 = \frac{84 - 80 }{ \frac{4.47 }{ \sqrt{10} } }[/tex]

   =>     [tex]t_1 = 2.8298[/tex]

  The second  test statistics is evaluated as

           [tex]t_2 = \frac{M - \mu }{ \frac{\sigma }{ \sqrt{n_2} } }[/tex]

=>       [tex]t_2 = \frac{84 - 80 }{ \frac{4.47 }{ \sqrt{20} } }[/tex]

=>       [tex]t_2 = 4.0[/tex]

The sample with the larger test statistics (sample  size) will more likely reject the null hypothesis

Generally the Cohen's d value is mathematically evaluated as

          [tex]d = \frac{M - \mu }{s }[/tex]

  =>     [tex]d = \frac{ 84 - 80 }{4.47 }[/tex]    

=>         [tex]d = 0.895[/tex]

Given that the the sample mean and  sample size are the same for both sample the Cohen's d value will be  the same      

Answer:

There is a positive correlation between these two variables.

Step-by-step explanation:

Positive correlation is an association amid two variables in which both variables change in the same direction.  

A positive correlation occurs when one variable declines as the other variable declines, or one variable escalates while the other escalates.

As the distance covered by the vehicle increases the amount of gas consumed also increases. Thus, the weekly cost of gas will also increase.

Thus, there is a positive correlation between these two variables.

Answer

$25.59

Step-by-step explanation:

subtract by percentage or you can also do:

100% - 4.5% = 95.5%

95.5% x $26.80 = $25.594

IF ROUNDED: $25.59

Answer:

$25.65

Step-by-step explanation:

Let the original hourly rate be r.  

Then 1.045r + $26.80/hr.

Dividing both sides by 1.045, we get:

      $26.80/hr

r = ------------------ = $25.65  This was the before-raise pay rate.

         1.045

Answer:

fucuvucybycych tcy bic ttx TV ubtx4 cub yceec inivtxr xxv kb

Step-by-step explanation:

t tcextvtcbu6gt CNN tx r.c tct yvrr TV unu9gvt e tch r,e xxv t u.un4crcuv3cinycycr xxv yctzrctvtcrzecycyvubr xiu nyfex tut uhyh

Answer:

x = -70

Step-by-step explanation:

x/10 = -7

Multiply each side by 10

x/10*10 = -7*10

x = -70

Step-by-step explanation:

Option A and B are the correct answer because it equal to 688.5 and 688.05

Answer:

it is 1377/2 and 688 1/17 thats the answer

Step-by-step explanation:

Answer:

t = 32,5 minutes

Step-by-step explanation:

Volume to fill =  13000000 Gal

5 pumps delivering  80000 gal/min

5 * 80000 = 400000 gal/min

If we divide the total volume by the amount of water delivered for the 5 pumps, we get the required time to fill the volume, then

t =  13000000/ 400000

t = 32,5 minutes

Answer:

Slope : 2

slope-intercept: y = 2x + 6

Point-slope (as asked): y - 4 = 2 (times) (x + 1)

standered: 2x - y = -6

Step-by-step explanation:

Answer:

Algebra deals with knowing the value of unknown variables and functional relationships, while trigonometry touches on triangles, sides and angles and the relationship between them.

Algebra is more on polynomial equations, x and y while trigonometry more on sine, cosine, tangent, and degrees.

Trigonometry is much more complicated than algebra but algebra has its uses in our daily lives, be it calculating distance from point to another or determining the volume of milk in a milk container.

Step-by-step explanation:

Answer:

Although both Algebra II and Trigonometry involve solving mathematical problems, Algebra II focuses on solving equations and inequalities while Trigonometry is the study of triangles and how sides are connected to angles.

hope this answer helps u

pls mark as brainliest .-.

Answer:

4

Step-by-step explanation:

i distributed the -2 to what's in the parentheses. that equal 0. I then moved the 4 to the zero so that it becomes positive. I just assumed that you were ask for Y

Step-by-step explanation:

y-4=-2(x+3)....eq(1)

y- 4= -2x-6

y=-2x-2...eq(2)

subtituting equation 2 in equation 1

(-2x-2)-4=-2x-6

-2x-6=-2x-6

=0

Answer:

12 units

Step-by-step explanation:

Since all of the sides of a rhombus are congruent, JK = JM which means:

2x + 4 = 3x

-x = -4

x = 4 so 3x = 3 * 4 = 12

Answer:

Step-by-step explanation:

Hello, I assume that you mean

[tex]x^2-5x-36[/tex]

The product is -36.

[tex]x_1 \text{ and } x_2 \text{ are the two roots, we can write}\\\\(x-x_1)(x-x_2)=x^2-(x_1+x_2)x+x_1\cdot x_2[/tex]

So in this example, it means that the sum is 5 and the product is -36.

Thank you

Correct question is ;

The grade appeal process at a university requires that a jury be structured by selecting eight individuals randomly from a pool of nine students and eleven faculty.​ (a) What is the probability of selecting a jury of all​ students? (b) What is the probability of selecting a jury of all​ faculty? (c) What is the probability of selecting a jury of six students and two ​faculty?

Answer:

A) 7.144 × 10^(-5)

B) 0.00131

C) 0.0367

Step-by-step explanation:

We are given;

Number of students = 9

Number of faculty members = 11

A) Now, the number of ways we can select eight students from 9 =

C(9, 8) = 9!/(8! × 1!) = 9

Also, number of ways of selecting 8 individuals out of the total of 20 = C(20,8) = 20!/(8! × 12!) = 125970

Thus, probability of selecting a jury of all​ students = 9/125970 = 7.144 × 10^(-5)

B) P(selecting a jury of all faculty) = (number of ways to choose 8 faculty out of 11 faculty)/(Total number of ways to choose 8 individuals out of 20 individuals) = [C(11,8)]/[C(20,8)] = (11!/(8! × 3!))/125970 = 0.00131

C) P(selecting a jury of six students and two faculty) = ((number of ways to choose 6 students out of 9 students) × (number of ways to choose 2 faculty out of 11 faculty))/(Total number of ways to choose 8 individuals out of 20 individuals) = [(C(9,6) × C(11,2)]/125970

This gives;

(84 × 55)/125970 = 0.0367

Answer:

1 square foot is the answer

Answer:

1 ft^2

Step-by-step explanation:

We know 12 inches = 1 ft

12 inches by 12 inches

1 ft by 1 ft

The area is 1 * 1 = 1 ft^2

Answer:

16

Step-by-step explanation:

4 * sqrt( a^2 - b^2)

Let a = -5 and b =3

4 * sqrt( (-5)^2 - 3^2)

Do the squaring first

4 * sqrt( 25 - 9)

Subtract inside the square root

4 * sqrt( 16)

Take the square root

4 * 4

Multiply 16

Answer:

[tex]\Large \boxed{16}[/tex]

Step-by-step explanation:

[tex]4\sqrt{a^2-b^2 }[/tex]

[tex]\sf Plug \ in \ the \ values \ for \ a \ and \ b.[/tex]

[tex]4\sqrt{-5^2-3^2 }[/tex]

[tex]4\sqrt{25-9 }[/tex]

[tex]4\sqrt{16}[/tex]

[tex]4 \times 4=16[/tex]