A Fifty dog owners and 50 people who do not own dogs are each given a test to evaluate their stress levels. Dog owners are found to have significantly lower stress levels than people who do not own dogs. Which of the following statements are true?
1. This study provides good evidence that owning a dog is effective in reducing stress.
2. It is likely that a confounding variable could be a contributing explanation for the difference between these two groups.
3. This is an observational study, not an experiment.
a. I only
b. II only
c. III only
d. II and III only
e. I and III only

Answers

Answer 1

Answer: 2. It is likely that a confounding variable could be a contributing explanation for the difference between these two groups.

3. This is an observational study, not an experiment.

Step-by-step explanation:

Based on the information given, the statement that's true include:

• It is likely that a confounding variable could be a contributing explanation for the difference between these two groups.

• This is an observational study, not an experiment.

It is an observational study as the researcher observed just observed the scenarios without him trying to change the people that are being exposed to it or controlling it.

Therefore, the correct options are II and III only.


Related Questions

Carlos downloaded a pattern from the Internet for making a table with an
irregular polygon-shaped top. The instructions on the pattern say that the
scale factor is 9/2. The sides of the pattern are shown on the diagram below.
What is the length of the longest side of the finished tabletop?

Answers

Answer:

it's b trust me i don't know how to explain my answer but it's b

Step-by-step explanation:

explanation

5
Ginny is baking mince pies.
(a) A recipe says to use 3000 g of mincemeat for 100 pies.
How many grams of mincemeat will she need for 70 pies?

Answers

It would be 2100.
3000/100=30
30•70=2100

Answer:2100g

Step-by-step explanation:

We can use ratios to solve this:

100 pie : 3000g

1 pie : 30g

70 pie : 2100g

A manufacturer of compact-disk players subjects the equipment to a comprehensive testing process for all mechanical and electrical functions before the equipment leave the factory. Ideally, the hope is that each compact-disk player passes on the first test. Suppose that past data indicate that the probability that a compact-disk player passes the first test is 0.9. If 4 compact-disk players are randomly selected, determine the probability for Question a-f and round your answer to four decimal places.

Answers

Answer:

Incomplete question, but the binomial distribution with [tex]p = 0.9[/tex] and [tex]n = 4[/tex] is used to solve the questions.

Step-by-step explanation:

For each disk, there are only two possible outcomes. Either it passes the first test, or it does not. The probability of a disk passing the first test is independent of any other disk. This means that the binomial probability distribution is used 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.

Suppose that past data indicate that the probability that a compact-disk player passes the first test is 0.9.

This means that [tex]p = 0.9[/tex]

4 compact-disk players are randomly selected

This means that [tex]n = 4[/tex]

Pat used unit cubes to build a right rectangular prism with a volume of 32 cubic units. The height of the prism is 4 units. What figure could be the bottom layer of the prism?

Answers

Answer:

It must be a rectangle with dimension of either 1 by 8  or 2 by 4

Step-by-step explanation:

V = l*w*h

32 = l*w*4

32/4 = l*w*4/4

8 = l*w

We could have 1*8

We could have 2*4

It must be a rectangle

It must be a rectangle with dimension of either 1 by 8  or 2 by 4

Name two acute angles

Answers

A because they are less than 90 degrees
the answer is A i promise you

Find the area of the figure it says. But I don’t know how? Can somebody explain.

Answers

Answer:

Area=120 cm

Step-by-step explanation:

I think for each separate figure you find the area and then add them up to find the total area. The formula to find the area here is length times width or base times height.

First figure: 12 times 5= 60 cm

Second figure=8 times 5=40cm

Together we have 100cm as our area, that might be wrong, look in the comments, thanks for correcting me :)

Find the length of x, round too the nearest tenth

Answers

Answer:

Step-by-step explanation:

take 72 degree as reference angle

using cos rule

cos 72=adjacent/hypotenuse

0.30=4/x

x=4/0.30

x=13.33

x=13.3

2/5 14.1/9 25/5 what is the improper fraction mixed number and common fraction​

Answers

Answer:

A mixed number is a whole number plus a fractional part. An improper fraction is a fraction where the numerator (top number) is larger than the denominator (bottom number). You can convert between mixed numbers and improper fractions without changing the value of the figure.

Step-by-step explanation:

i did it before

A stack of cards consists of seven red and four blue cards. A second stack of cards consists of eleven red cards. A stack is selected at random and three of its cards are drawn. If all of them are red, what is the probability the rst stack was selected

Answers

Answer:

0.1733 = 17.33% probability the first stack was selected.

Step-by-step explanation:

To solve this question, it is needed to understand conditional probability, and the hypergeometric distribution.

Hypergeometric distribution:

The probability of x sucesses is given by the following formula:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

In which:

x is the number of sucesses.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

[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]

Conditional probability:

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

Probability of all red cards for the first stack:

For this, we use the hypergeometric distribution, as the cards all chosen without replacement.

7 + 4 = 11 cards, which means that [tex]N = 11[/tex].

7 red, which means that [tex]k = 7[/tex]

3 are chosen, which means that [tex]n = 3[/tex]

We want all red, so we find P(X = 3).

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

[tex]P(X = 3) = h(3,11,3,7) = \frac{C_{7,3}*C_{4,0}}{C_{11,3}} = 0.2121[/tex]

Conditional probability:

Event A: All red

Event B: From the first stack.

Probability of all red cards:

0.2121 of 50%(first stack)

1 of 50%(second stack). So

[tex]P(A) = 0.2121*0.5 + 1*0.5 = 0.60605[/tex]

Probability of all red cards and from the first stack:

0.21 of 0.5. So

[tex]P(A \cap B) = 0.21*0.5 = 0.105[/tex]

What is the probability the first stack was selected?

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.105}{0.60605} = 0.1733[/tex]

0.1733 = 17.33% probability the first stack was selected.

What is the formula for margin of error?The triangles below are similar. Triangle A B C. Side A C is 10 and side A B is 5. Angle C is 30 degrees. Triangle D E F. Side E D is 7.5 and side D F is 25. Angle F is 30 degrees and angle E is 90 degrees. Which similarity statements describe the relationship between the two triangles? Check all that apply.

Answers

Answer:

d

Step-by-step explanation:

Will give brainliest to whoever answers first and correct

Answers

Answer:

A is f(t)=-(t-4)^2+50

B is 50. the top of the graph is at 50

C is at 4. that is the x value when y=50

If you need the graph put the answer from question A into Desmos

I need help ASAP please

Answers

Answer:

The perimeter is 35 units

Step-by-step explanation:

Given

The attached shape

Required

The perimeter of the shape

From the shape, we have:

[tex]AB = 11[/tex]

[tex]AD = 8[/tex]

[tex]BD = AD = 8[/tex] --- sides of an isosceles

Also:

[tex]BC = DC = BD = 8[/tex] --- sides of an equilateral

So, the perimeter (P) is:

[tex]P = AB + BC + DC + AD[/tex]

[tex]P = 11 + 8 + 8 + 8[/tex]

[tex]P = 35[/tex]

Properties of Isosceles triangles

2 sides are equal

2 angles are equal

Properties of equilateral triangles

All sides are equal

All angles are equal

Help plz I don’t rlly know

Answers

Answer:

13 ft

Step-by-step explanation:

Perimeter is 48 so all four sides add to 48

You know width is 11 so 2x11 is 22.

Subtract the width from the total 48-22=26

Then because you are missing 2 sides divide the answer by 2.

26/2=13

Plane A is flying at 440 mph in the northeast direction relative to the Earth. Plane B is flying at 550 mph in the north direction relative to the Earth. What is the speed of Plane B as observed from Plane A?a. 532 mphb. 860 mphc. 362 mphd. 659 mphe. 669 mph

Answers

Answer:

The speed of plane B relative to plane A is 392.25 mph.

Step-by-step explanation:

Speed of plane A = 440 mph north east

speed of plane B = 550 mph north

speed of plane A = [tex]440(cos 45 \widehat{i} + sin 45 \widehat{j})=311.1 \widehat{i} + 311.1 \widehat{j}[/tex]

speed of plane B = [tex]550 \widehat{j}[/tex]

Speed  of plane B with respect to plane A is

= speed of plane B - speed of plane A

[tex]=550 \widehat{j} - 311.1 \widehat{i} - 311.1 \widehat{j}\\\\=-311.1 \widehat{i} + 238.9 \widehat{j}\\\\= \sqrt{311.1^2 + 238.9^2 }\\\\=392.25 mph[/tex]

What is the value of f(-4)

Answers

Answer:

the correct answer is 10

Step-by-step explanation:

Which number line shows the solution set for |a|= 6

Answers

Answer:

O the first number line

Step-by-step explanation:

|a| = 6

|?| = absolute value

to find absolute value of a number, it must be a opposite number from the origina number

|a| = 6

|-6| = 6

6 = 6  

Answer:

A)

Step-by-step explanation:

3. The number of sheets of paper available for making notebooks is 78,000. Each
sheet of paper makes 8 pages of a notebook. If each notebook contains 192
pages, find the number of notebooks that can be made from the paper available?​

Answers

Answer:

3250

Step-by-step explanation:

Answer:

I believe the answer is 3,250

78,000 x 8 = 624,000

624,000 / 192 = 3,250

Find the difference.
(-3ab-a-3) - (6ab+1)

Answers

Answer:

-9ab-a-4

Step-by-step explanation:

(-3ab-a-3) - (6ab+1)

Distribute the minus sign

(-3ab-a-3) - 6ab-1

Combine like terms

-9ab-a-4

Answer:

[tex]-9ab-a-4[/tex]

Step-by-step explanation:

Hi there!

[tex](-3ab-a-3)-(6ab+1)[/tex]

Open up the parentheses

[tex]-3ab-a-3-6ab-1[/tex]

Combine like terms

[tex]-3ab-6ab-a-3-1\\-9ab-a-3-1\\-9ab-a-4[/tex]

I hope this helps!

The distribution of passenger vehicle speeds traveling on a certain freeway in California is nearly normal with a mean of 73.7 miles/hour and a standard deviation of 4.72 miles/hour. The speed limit on this stretch of the freeway is 70 miles/hour.
(a) A highway patrol officer is hidden on the side of the freeway. What is the probability that 5 cars pass and none are speeding?
Assume that the speeds of the cars are independent of each other. (Round your answer to four decimal places.)
(b) On average, how many cars would the highway patrol officer expect to watch until the first car that is speeding?
(c) What is the standard deviation of the number of cars he would expect to watch?

Answers

Answer:

a)  0.2347, 0.0007

b) 1.30

c) 0.63

Step-by-step explanation:

Given –  

Mean = 73.4

Sigma = 4.7

Probability that the speed is greater than 70 is  

P (X>70) = P (z> (70-73.4)/4.7) = P (z>-0.72) = 0.7653

a) The probability that a car is not speeding = 1 - 0.7653 = 0.2347

The probability that all 5 cars are not speeding = (0.2347)5 = 0.0007

b) E (X) = 1/p = 1/0.7653 = 1.30  

c) Standard deviation = Sqrt (1-p/p) = (1-0.7653)/0.7653 = 0.63


You want to buy a pair of shoes that usually cost $100. Today the store is
having a sale: 20% off everything.
You also have a coupon that
promises 10% off the price at the
register. How much do you save? *

Pls help and pls show how you got it! I am very confused.

Thank you

Answers

Answer:

You saved $30

Step-by-step explanation:

20% + 10% = 30%

30% = 0.30

$100 * 0.30 = $30

$100 - $30 = $70

Hope this is helpful

Which statement implies that A and B are independent events?
O A. P(B|A) = P(B N A)
O B.
P(BA) = P(B)
P(A)
O C.
P(B|A) = P(A)
OD.
P(BA) = P(B)

Answers

Answer:

[tex]P(A \cap B) = P(A)P(B)[/tex]

Step-by-step explanation:

Independent events:

If two events, A and B are independent, the probability of both A and B happening is the same as the probability of A happening multiplied by the probability of B happenings, that is:

[tex]P(A \cap B) = P(A)P(B)[/tex]

In this question:

The statement is [tex]P(A \cap B) = P(A)P(B)[/tex]

PLEASEEEEEE I REALLY NEED HELPPPP WITH THIS PLEASEEEEEE IM BEGGING SOMONEEEE PLEASEEEE PLEASEEEE PLEASEEEEEE​

Answers

Answer:

y > (1/2)x + 2

Step-by-step explanation:

The line rises 1 in y for each run of 2 in x

slope = rise/run

slope = 1/2

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

The y-intercept is 2

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

The graph is shaded above the dashed line

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

Therefor

y > (1/2)x + 2

Answer:

y>1/2x+2

Step-by-step explanation:

The answer is y>1/2x+2. The shaded red part is the graph of y>1/2x+2. Because the slope is 1/2 and the y-intercept is 2, this is the correct answer.

If this helps please mark as brainliest

Given AD|GJ. Refer to the figure and provide an appropriate name for

Answers

Check the picture below.

There are 20 families living in the Willbrook Farms Development. Of these families, 10 prepared their own federal income taxes for last year, 7 had their taxes prepared by a local professional, and the remaining 3 by H&R Block. a) What is the probability of selecting a family that prepared their own taxes? b) What is the probability of selecting two families, both of which prepared their own taxes?

Answers

Answer:

a) 1/2

b) 9/40

Step-by-step explanation:

Given

Total number of families living in Willbrook Farms Development = 20

Number of families preparing their own federal income taxes for last year = 10

Number of families for which taxes were prepared by a local professional = 7

Number of families for which taxes were prepared by H&R Block = 3

a) Probability of selecting a family that prepared their own taxes = 10/20 = 1/2

b) The probability of selecting two families, both of which prepared their own taxes

10/20 * 9/20 = 9/40

Assuming the speed of sound is 340 m/s ..

Answers

Answer:

You did not finish the question. If you were to finish it, we might be able to help you.

You have to put the full question first

What is the nth term rule of the linear sequence below?
22
,
18
,
14
,
10
,
6
,
.
.
.

Answers

Answer:

tn=a+(n-1)d

tn=22+(n-1)4

tn=22+4n-4

tn=4n+18

What is filtration??​

Answers

▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓

[tex]\pmb{\qquad{\qquad{\qquad{\underline{\green{\underline{\sf{Filtration}}}}}}}}[/tex]

Filtration is a physical or chemical separation process that separates solid matter and flu.id from a mixture using a filter medium that has a complex structure through which only the flu.id can pa.ss.

▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓



Order the numbers from least to greatest to least 4,-2,2,0,3

Answers

Answer:-2, 0, 2, 3, 4

Step-by-step explanation:

-2 is smaller than 0, 0 is smaller than 2, 2 is smaller than 3, and 3 is smaller than 4.

Answer:

4, 3, 2, 0, -2

f(2)=
Please help I don’t got time ;-;

Answers

Answer:

b

Step-by-step explanation:

h

A long-term period of economic recession that leads to a low GDP and very high unemployment is a(n)

A. Trough
B. expansion
C. depression
D. Contraction​

Answers

Answer:

The answer is C. Depression.

Step-by-step explanation:

Depression is defined as a severe and prolonged recession. Declining economic activity is characterized by falling output and employment levels. Generally, when an economy continues to suffer recession for two or more quarters, it is called depression.

The level of productivity in an economy falls significantly during a depression. Both the GDP (gross domestic product) and GNP (gross national product) show a negative growth along with greater business failures and unemployment. Depressions are relatively less frequent than milder recessions, and tend to be accompanied by high unemployment and low inflation.

C depression I’m just answering for points
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