Given the system:

2x – 4y = -34

-3x - y = 2

Solve for the variables that make up the coefficient

matrix:

[a b]

[c d]

a=

b =

c=

d=

Answer:

The probability that the average age of a randomly selected sample of 100 students will be less than 21.8 years is 0.159

Step-by-step explanation:

According to the given data we have the following:

mean = μ= 22

standard deviation = σ = 2

n = 100

μx = 22

σx=σ/√n=2/√100=0.2

Therefore, P( x < 21.8)=P(x-μx)/σx<(21.8-22)/0.2

=P(z<-1)

= 0.159

The probability that the average age of a randomly selected sample of 100 students will be less than 21.8 years is 0.159

Answer:

c and d

Step-by-step explanation:

the x intercepts are the solutions

Answer:

(0,2) and (-5,0)

Step-by-step explanation:

the point where the two graph lines meet would be the answer.

Answer:

y≤4

Step-by-step explanation:

y≤4

try to graph it on a parabola and u will find the answer above :D hope this helped

Answer:

C. Between 175 and 295 dollars.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 235

Standard deviation = 20

According to the Standard Deviation Rule, almost all (99.7%) of the students spent on textbooks in a semester:

Within 3 standard deviations of the mean.

235 - 3*20 = 175

235 + 3*20 = 295

So the correct answer is C.

Answer: there are 4 solutions

x = -2

x = -1/2 = -0.500

x =(3-√5)/2= 0.382

x =(3+√5)/2= 2.618

Step-by-step explanation:

Answer:

The average population growth per year is 102.

Step-by-step explanation:

From the given data, we can find the slope which will give us the average rate of change. Our points are:

[tex](2003, 903)\quad and \quad (2007, 1311)[/tex]

[tex]\mathrm{Slope}=\frac{y_2-y_1}{x_2-x_1}=\frac{1311-903}{2007-2003}\\\\m=102[/tex]

Best Regards!

Answer:

0.1905 = 19.05%

Step-by-step explanation:

We have a total of 106 containers of oxygen, from which:

20 have oxygen not ionized, 86 have oxygen ionized.

If the first one selected is ionized, now we have 20 not ionized and 85 ionized.

So the probability of the second one selected being not ionized is the number of not ionized (20) over the total number of containers (20 + 85):

P = 20 / (20 + 85) = 0.1905 = 19.05%

Answer:

m = -2/3

Step-by-step explanation:

Slope Formula: [tex]m = \frac{y2-y1}{x2-x1}[/tex]

So,

[tex]m = \frac{-1-1}{9-6}[/tex]

m = -2/3

Answer:

[tex]z=\frac{31.1-31.3}{\frac{1.3}{\sqrt{140}}}=-1.82[/tex]  

The p value for this case would be given by:

[tex]p_v =2*P(z<-1.82)=0.0688[/tex]  

For this case since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true mean is not significantly different from 31.3 MPG

Step-by-step explanation:

Information given

[tex]\bar X=31.1[/tex] represent the sample mean  

[tex]\sigma=1.3[/tex] represent the population standard deviation

[tex]n=140[/tex] sample size  

[tex]\mu_o =31.3[/tex] represent the value that we want to test  

[tex]\alpha=0.02[/tex] represent the significance level for the hypothesis test.  

z would represent the statistic

[tex]p_v[/tex] represent the p value

Hypothesis to test

We want to test if the true mean is equal to 31.3 MPG, the system of hypothesis would be:  

Null hypothesis:[tex]\mu =31.3[/tex]  

Alternative hypothesis:[tex]\mu \neq 31.3[/tex]  

Since we know the population deviation, the statistic is given by

[tex]z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}[/tex] (1)  

Replacing we got:

[tex]z=\frac{31.1-31.3}{\frac{1.3}{\sqrt{140}}}=-1.82[/tex]  

The p value for this case would be given by:

[tex]p_v =2*P(z<-1.82)=0.0688[/tex]  

For this case since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true mean is not significantly different from 31.3 MPG

Answer:

Type II error.

Step-by-step explanation:

We have a hypothesis test for the claim that placing a seasonal cookie product on an end cap (the shelf at the end of an aisle at a store) will make a difference in sales.

The null hypothesis will state that there is no difference, while the alternative hypothesis will state that there is significant positive difference.

The result is a P-value of 0.1288 and the null hypothesis failing to be rejected.

As the null hypothesis failed to be rejected, if an error has been made in the conclusion, is that we erroneusly accept a false null hypothesis.

This is a Type II error, where the null hypothesis is accepted although the alternative hypothesis is true.

Answer:

Not sure 3/10?

Step-by-step explanation:

numbers are 0-9...that's 10 choices.

he chooses 3 numbers

I would think 3/10?

Answer:

27.11% probability that 2 of them have blue eyes

Step-by-step explanation:

For each person, there are only two possible otucomes. Either they have blue eyes, or they do not. The probability of a person having blue eyes is independent of any other person. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

8% of all people have blue eyes.

This means that [tex]p = 0.08[/tex]

Random sample of 20 people:

This means that [tex]n = 20[/tex]

What is the probability that 2 of them have blue eyes?

This is P(X = 2).

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 2) = C_{20,2}.(0.08)^{2}.(0.92)^{18} = 0.2711[/tex]

27.11% probability that 2 of them have blue eyes

The probability that 2 of them have blue eyes is 27.11%.

Given that,

Approximately 8% of all people have blue eyes.

Out of a random sample of 20 people,

We have to determine,

What is the probability that 2 of them have blue eyes?

According to the question,

People having blue eyes p = 8% = 0.08

Sample of people n = 20

For each person, there are only two possible outcomes. Either they have blue eyes, or they do not.

The probability of a person having blue eyes is independent of any other person.

The probability that 2 of them have blue eyes is determined by using a binomial probability distribution.

[tex]\rm P (X = x) =n_C_x\times p^x \times (1-p)^{n-x}}[/tex]

Therefore,

The probability that 2 of them have blue eyes is,

[tex]\rm P (X = x) =n_C_x\times p^x \times (1-p)^{n-x}}\\\\ \rm P (X = x) = \dfrac{n!}{(n-x)! \times x!} \times p^x \times (1-p)^{n-x}}\\\\[/tex]

Substitute all the values in the formula,

[tex]\rm P (X = 2) = \dfrac{20!}{(20-2)! \times 2!} \times (0.08)^2 \times (1-0.08)^{20-2}}\\\\ P (X = 2) = \dfrac{20!}{(18)! \times 2!} \times (0.0064) \times (0.92)^{18}}\\\\ P (X = 2) = \dfrac{19\times 20}{ 2} \times (0.0064) \times (0.222)\\\\ P(X = 2) = {19\times 10}\times (0.00142)\\\\P(X = 2) = 0.2711\\\\P(X = 2) = 27.11 \ Percent[/tex]

Hence, The required probability that 2 of them have blue eyes is 27.11%.

For more details refer to the link given below.

https://brainly.com/question/23640563

Answer:

60

Step-by-step explanation:

x=60 .

The triangle is equilateral and x=60 cause the two lines are ||

a. x=60°

b. Alternate interior angles

Solution,

Given,

All sides of triangle are equal.

AB=BC=AC

<ABC=<ACB=<BAC=y

By angle sum property of triangle,

<ABC+<BCA+<CAB=180

or y+y+y=180

or 3y=180

or y=180/3

y=60

Now,

<ACB=<CAD

<CAD(x)=60( Alternate interior angles)

Hope this helps ..

Good luck on your assignment..

Answer:

A. y = 7(x + 1)²-3

Step-by-step explanation:

Parabola:

[tex]y = 7x^{2} + 14x + 4[/tex]

[tex]y = 7(x^{2} + 2x) + 4[/tex]

Putting into vertex form, remember that:

[tex](x + a)^{2} = x^{2} + 2ax + a^{2}[/tex]

In this question:

[tex]x^{2} + 2x[/tex], to put into this format:

[tex]x^{2} + 2x + 1 = (x + 1)^{2}[/tex]

We add one inside the parenthesis to do this. The parenthesis is multiplied by 7, so for the equivalent, we also have to subtract 7. Then

Vertex form:

[tex]y = 7(x^{2} + 2x + 1) + 4 - 7[/tex]

[tex]y = 7(x + 1)^{2} - 3[/tex]

So the correct answer is:

A. y = 7(x + 1)²-3

Answer:

7:1

Step-by-step explanation:

28:4=

7(4):1(4)=

7:1

Hope this helps!

Answer:

[tex]7:1[/tex]

Step-by-step explanation:

[tex]28:4[/tex]

Common highest factor is 4.

Simplify the ratio.

[tex]28 \div 4 : 4 \div 4[/tex]

[tex]7:1[/tex]

Answer:

[tex](\frac{-1}{2} , \frac{-\sqrt{3} }{2} )[/tex]

Step-by-step explanation:

Memorize your unit circle.

Step 1: Subtract 360 from 600 degrees to find rotation

600° - 360° = 240°

Step 2: Either find coordinates from unit circle or convert to radians

240° = 4π/3

Step 3: Find coordinates

Answer:

3422 x232

Step-by-step explanation:

Answer:

180

Step-by-step explanation:

2(24)-3=45

24-8=√16=4

45*4=180

Answer:

it it the highest or lowest point of a parabola

Answer:

[tex]18\sqrt{10}$ units[/tex]

Step-by-step explanation:

We are given the equation of the line y=3x and a point, say Q(60,0) outside of that line.

We want to find the point on the line y=3x which is closest to Q.

Let P(x,y) be the desired point. Since it is on the line y=3x, it must satisfy the line.

If x=a, y=3a, so the point P has the coordinates (a,3a).

Distance between point Q and P

[tex]=\sqrt{(60-a)^2+(0-3a)^2}\\D =\sqrt{10a^2-120a+3600}[/tex]

To minimize D, we find its derivative

[tex]\dfrac{dD}{da}=\dfrac{10a-60}{\sqrt{10a^2-120a+3600} }\\$Setting \dfrac{dD}{da}=0\\10a-60=0\\10a=60\\a=6[/tex]

Therefore, the y-coordinate for P is 3*6=18.

The point P=(6,18).

Next, we calculate the distance between P(6,18) and (60,0).

[tex]D =\sqrt{10(6)^2-120(6)+3600}\\=\sqrt{3240}\\=18\sqrt{10}$ units[/tex]

Answer:

The type of observational study describer here is retrospective study.

Step-by-step explanation:

The complete question is:

Vitamin D is important for the metabolism of calcium and exposure to sunshine is an important source of vitamin D. A researcher wanted to determine whether osteoperosis was associated with a lack of exposure to sunshine. He selected a sample of 250 women with osteoperosis and an equal number of women without osteoperosis. The two groups were matched - in other words they were similar in terms of age, diet, occupation, and exercise levels. Histories on exposure to sunshine over the previous twenty years were obtained for all women. The total number of hours that each woman had been exposed to sunshine in the previous twenty years was estimated. The amount of exposure to sunshine was compared for the two groups. Determine what type of observational study is described. Explain.

Solution:

In retrospective study design, the concerned outcome has previously taken place in each participant by the phase he or she is signed up for the study, and the information are gathered either from past data or by requesting the participants to recall exposures.

It is also known as a historic cohort study.

A retrospective study is completed as posterior experiment, using data on events that have already taken place in the history. In most cases some or most of the data has already been collected and stowed in the archive.

In the provided scenario, the researcher collect the past data for the exposure to sunshine over the previous twenty years for 250 women. And estimated the  total number of hours that each woman had been exposed to sunshine in the previous twenty years.

Then the researcher compares the amount of exposure to sunshine for the two groups.

Thus, the type of observational study describer here is retrospective study.

Answer:

Step-by-step explanation:

Add the two equations together:

  (x -y) +(x +y) = (34) +(212)

  2x = 246

  x = 123

  y = x-34 = 89

Malik has 89 foreign stamps and 123 domestic stamps.

Answer:

89 and 123

Step-by-step explanation:

Answer:

not 100% sure but my answer is 110

Step-by-step explanation:

It is More Affordable and is the better Buy From All the other choices.

Answer:

670 Cans of fruit will be left

Step-by-step explanation:

First you multiply 155 by the 6 weeks.

That equals 930 and then you subtract 930 from 1,600 and that gives you 670.

There are 670 cans of fruit that will remain after 6 weeks the answer is 670 cans.

It is defined as the systematic way of representing the data that follows a certain rule of arithmetic.

We have:

The local food pantry has 1, 600 cans of fruit. They give away 155 cans of fruit each week.

First term a = 1600

Common difference d = -155

After 6 weeks means on week 7.

n = 7

a(7) = 1600 + (7-1)(-155)

a(7) = 1600 - 930

a(7) = 670

Thus, there are 670 cans of fruit that will remain after 6 weeks the answer is 670 cans.

Learn more about the sequence here:

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Answer:

44.80% probability that in a given week he will sell 2 or more policies but less than 4 policies.

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]

In which

x is the number of sucesses

e = 2.71828 is the Euler number

[tex]\mu[/tex] is the mean in the given interval.

A life insurance salesman sells on the average 3 life insurance policies per week.

This means that [tex]\mu = 3[/tex]

Calculate the probability that in a given week he will sell 2 or more policies but less 4 policies.

[tex]P(2 \leq X < 4) = P(X = 2) + P(X = 3)[/tex]

In which

[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]

[tex]P(X = 2) = \frac{e^{-3}*3^{2}}{(2)!} = 0.2240[/tex]

[tex]P(X = 3) = \frac{e^{-3}*3^{3}}{(3)!} = 0.2240[/tex]

[tex]P(2 \leq X < 4) = P(X = 2) + P(X = 3) = 0.2240 + 0.2240 = 0.4480[/tex]

44.80% probability that in a given week he will sell 2 or more policies but less than 4 policies.

Answer:

Step-by-step explanation:

Claim: if the mean amount of garbage per bin is different from 50.

Null hypothesis: u=50

Alternative hypothesis : u =/ 50

Using the z score formular for a one sample z test - z = (x - u ) / (sd/√n)

Where x = 48.99, u = 50 sd =3.7 and n = 36

z = 48.99 - 50 / (3.7/√36)

z = -1.01 / (3.7/6)

z = -1.01/0.6167

z = -1.6377

To find the p value at a 0.01 level of significant from the -1.6377 z score for a two tailed test the p value using the p value calculator is 0.1016. The result is not significant at 0.01 level of significant thus we will fail to reject the null and conclude that the mean amount of garbage per bin is 50.

Answer:

ge

Step-by-step explanation:

ge

Answer:

its 2pi/3

Step-by-step explanation:

because the full radian measure of a circle is 2pi radians, the smaller circle is a third of the size of the larger one. Multiply straight across for (2pi/1)(1/3)  

The circumference of the smaller circle can be given by [tex]\dfrac{2\times \pi}{m}(x)\ units[/tex].

[tex]\rm{Circumference\ of\ the\ circle = 2\times \pi \times (radius)[/tex]

[tex]\rm{Circumference\ of\ the\ circle = 2\times \pi \times (OB)[/tex]

[tex]\rm{Circumference\ of\ the\ circle = 2\times \pi \times (x)[/tex]

Circumference of the Larger circle = 3 x Circumference of the smaller circle

[tex]2\times \pi \times x = 3\times Circumference\ of\ the\ smaller\ circle\\\\3\times Circumference\ of\ the\ smaller\ circle = 2\times \pi \times x \\\\Circumference\ of\ the\ smaller\ circle = \dfrac{2\times \pi \times x }{3}\\\\Circumference\ of\ the\ smaller\ circle = \dfrac{2\times \pi}{3}( x )\ units[/tex]

Hence, the circumference of the smaller circle can be given by [tex]\dfrac{2\times \pi}{m}(x)\ units[/tex].

Learn more about similar circles:

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