can some one answer this plsss

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:

x<16

Step-by-step explanation:

number n

eight less than four times a number ... 4 x n - 8

is less than 56 ... < 56

4 x n - 8 < 56

4 x n < 56 + 8

4 x n < 64/4

n < 64 / 4

n < 16

Answer:

Step-by-step explanation:

Let the number be x

Four times the number :  4x

Eight less than four times a number: 4x - 8

4x - 8 < 56

Now add 8 to both sides,

4x < 56+8

4x < 64

Divide both sides by 4,

x < 64/4

x < 16

Possible values of number = Value less than 16

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:

It is only (5,24).

Step-by-step explanation:

You are correct.

Sometimes, check all options means there could be just one option.

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.

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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:

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:

14.4 units

Step-by-step explanation:

In Trigonometry

[tex]\cos \theta =\frac{Adjacent}{Hypotenuse}\\[/tex]

In Triangle DEF,

[tex]\cos F =\dfrac{EF}{DF}\\\cos 26^\circ =\dfrac{EF}{16}\\EF=16 \times \cos 26^\circ\\=14.4$ units (correct to the nearest tenth).[/tex]

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.

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Answer:

[tex]-4x+28[/tex]

Step-by-step explanation:

[tex]18-2(x+x-5)[/tex]

[tex]18+(-2)(x)+(-2)(x)+(-2)(-5)[/tex]

[tex]18+-2x+-2x+10[/tex]

[tex]-2x-2x+10+18[/tex]

[tex]=-4x+28[/tex]

Answer:

2.4 hours

Step-by-step explanation:

If Mary is running 26 miles at a pace of 7.5 miles per hour, it will take her 3.47 hours to run the full course.

26/7.5 = 3.466666...

If she has run 8 miles, 1.07 hours have passed.

8/7.5 = 1.06666666...

Subtract the total time from the time that has already passed to find the time left.

3.47 - 1.07 = 2.4

Mary has 2.4 hours left.

Answer: 38 23/24

Step-by-step explanation:

Turn the mixed numbers into improper fractions

5 * 3 = 15

15 + 2 = 17

17/3

————————

6 * 8 = 48

48 + 7 = 55

55/8

————————

Now multiply the improper fractions

17/3 * 55/8

17 * 55 = 935

3 * 8 = 24

Divide 935 by 24 to get the answer as a mixed number.

935 / 24 = 38.95833

0.95833/1 = 23/24

935/24 as a mixed number is 38 23/24

Answer: 119 / 4

Step-by-step explanation:

5 2/3 x 6 7/8

= 17/3 x 6 x 7/8

= 17 x 2 x 7/8

= 17 x 2 x 7/8

= 17 x 7/4

= 119 / 4

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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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:

0.637

Step-by-step explanation:

The average value of a whole sinusoidal waveform over one complete cycle is zero as the two halves cancel each other out

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

its -1

Step-by-step explanation:

ED 2020 boiiiii

The residual value of the line of the best fit when x = 2 is -1

The equation of the line is given as:

y = 0.5x + 1

When x = 2, we have:

y = 0.5 * 2 + 1

Evaluate

y = 2

The residual is the difference between the actual value and the predicted value.

From the complete graph, the actual value is 1.

So, we have:

Residual = 1 - 2

Evaluate

Residual = -1

Hence, the residual value when x = 2 is -1

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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:

Due to the higher coefficient of variation, 2009's GMAT scores show a more dispersed distribution

Step-by-step explanation:

To verify how dispersed a distribution is, we find it's coefficient of variation.

Coefficient of variation:

Mean of [tex]\mu[/tex], standard deviation of [tex]\sigma[/tex]. The coefficient is:

[tex]CV = \frac{\sigma}{\mu}[/tex]

Which year's GMAT scores show a more dispersed distribution

Whichever year has the highest coefficient.

2009:

Mean of 500, standard deviation of 90. So

[tex]CV = \frac{90}{500} = 0.18[/tex]

2010:

Mean of 570, standard deviation of 85.5. So

[tex]CV = \frac{85.5}{570} = 0.15[/tex]

Due to the higher coefficient of variation, 2009's GMAT scores show a more dispersed distribution

2009's GMAT scores show a more dispersed distribution.

Given that in 2009: Mean = 500 and standard deviation = 90.

In 2010: Mean = 570 and standard deviation = 85.5.

If the standard deviation is higher then the scores will be more dispersed.

Note that: 90 > 85.5. And 90 corresponds to 2009.

So, 2009's GMAT scores show a more dispersed distribution.

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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:

ge

Step-by-step explanation:

ge

Answer:

Triangular Prism

volume 748

Answer:

it it the highest or lowest point of a parabola

Answer:

d = 234.6 m

Step-by-step explanation:

You can consider a system of coordinates with its origin at the beginning of the walk of the student.

When she start to walk, she is at (0,0)m. After her first walk, her coordinates are calculated by using the information about the incline and the distance that she traveled:

[tex]x_1=60cos28\°=52.97m\\\\y_1=60sin28\°=28.16m[/tex]

she is at the coordinates (52.97 , 28.16)m.

Next, when she walks 180m to the east, her coordinates are:

(52.97+180 , 28.16)m = (232.97 , 28.16)m

To calculate the distance from the final point of the student to the starting point you use the Pythagoras generalization for the distance between two points:

[tex]d=\sqrt{(x-x_o)^2+(y-y_o)^2}\\\\x=232.97\\\\x_o=0\\\\y=28.16\\\\y_o=0\\\\d=\sqrt{(232.97-0)^2+(28.16-0)^2}m=234.6m[/tex]

The displacement of the student on her complete trajectory was of 234.6m

Answer: Working together, they can complete the task in 7 hours and 12 minutes.

Step-by-step explanation:

Ok, Briana needs 12 hours to complete the task.

Then we can find the ratio of work over time as:

1 task/12hours = 1/12 task per hour.

This means that she can complete 1/12 of the task per hour.

Henry needs 18 hours to complete the task, then his ratio is:

1 task/18 hours = 1/18 task per hour.

This means that he can complete 1/18 of the task in one hour.

If they work together, then the ratios can be added:

R = 1/12 + 1/18 = 18/(12*18) + 12/(18*12) = 30/216

we can reduce it to:

R = 15/108 = 5/36

So, working together, in one hour they can complete 5/36 of the task, now we can find the number of hours needed to complete the task as:

(5/36)*x = 1 task

x = 36/5 hours = 7.2 hours

knowing that an hour is 60 minutes, then 0.2 of an hour is 60*0.2 = 12 minutes.

then x = 7 hours and 12 minutes.

Answer:

The rental of each chair is $2.75

The rental of each table is $8.5

Step-by-step explanation:

Let's name the unknowns "c" for the cost of each chair rental, and "t" for the cost of each table rental.

Now we can create the equations that represent the statements:

a) "The total cost to rent 2 chairs and 3 tables is $31."

2 c + 3 t = 31

b) "The total cost to rent 6 chairs and 5 tables is $59."

6 c + 5 t = 59

now we have a system of two equations and two unknowns that we proceed to solve via the elimination method by multiplying the first equation we got by "-3" so by adding it term by term to the second equation, we eliminate the variable "c" and solve for "t":

(-3) 2 c + (-3) 3 t = (-3)  31

-6 c - 9 t = -93

6 c + 5 t = 59

both these equations added give:

0 - 4 t = -34

t = 34/4 = 8.5

So each table rental is $8.5

now we find the rental price of a chair by using any of the equations:

2 c + 3 t = 31

2 c + 3 (8.5) = 31

2 c + 25.5 = 31

2 c = 5.5

c = 5.5/2

c = $2.75

Answer:

Step-by-step explanation:

                              Y

p(x,y)            0          1            2

           0      0.10     0.04     0.02

x          1       0.08     0.2     0.06

            2       0.0      0.14     0.30

a) What is P(X = 1 and = 1)

From the table above we have

P(1,1) = 0.2

b)  Compute P(X ≤ 1 and Y ≤ 1).

[tex]=p(0,0)+p(0,1)+p(1,0)+p(1,1)\\\\=0.1+0.04+0.08+0.2\\\\=0.42[/tex]

C)

Let A ={X ≠ 0 and Y ≠ 0}

p{X ≠ 0 , Y ≠ 0}

= p(1,1) + p(1,2) + p(2,1) + p(2,2)

= 0.20 + 0.06 + 0.14 + 0.30

=0.7

d) The possible X values are in the figure 0,1,2

[tex]p_x(0)=p(0,0)+p(0,1)+p(0,2)\\\\=0.1+0.04+0.02\\\\=0.16\\\\p_x(1)=p(1,0)+p(1,1)+p(1,2)\\\\=0.08+0.2+0.06\\\\=0.34\\\\p_x(2)=p(2,0)+p(2,1)+p(2,2)\\\\=0.06+0.14+0.3\\\\=0.5[/tex]

The possible Y values are in the figure 0,1,2

[tex]p_y(0)=p(0,0)+p(1,0)+p(2,0)\\\\=0.1+0.08+0.06\\\\=0.24\\\\p_y(1)=p(0,1)+p(1,1)+p(2,1)\\\\=0.04+0.2+0.14\\\\=0.38\\\\p_y(2)=p(0,2)+p(1,2)+p(2,2)\\\\=0.02+0.06+0.3\\\\=0.38[/tex]

So the probability of x ≤ 1 is

[tex]p(x\leq 1)=p_x(0)+p_x(1)\\\\=0.34+0.16\\\\=0.50[/tex]

e) From the table

[tex]p_x(x=1,y=1)=p(1,1)\\\\=0.2\\\\p_x(1)=0.34\\\\p_y(1)=0.38[/tex]

we multiply both together

0.34  x 0.38

=0.1292

Therefore p(1,1) is not equal px(1), py(1)

Hence x and y are not independent it is not equal

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:

1.36364

Step-by-step explanation:

I calculated the solution on a calculator

So the answer to 1 d.p is 1.4