Two methods are proposed to measure the effectiveness of a brand of sunscreen.

Method A: Survey adults visiting a beach on a busy weekend. Ask each adult which brand of sunscreen they are using, and assess their arms for sun exposure.

Method B: Volunteers are randomly assigned to one of two brands of sunscreen. Each volunteer is asked to report back at the end of the day, and their arms are assessed for sun exposure.

Which statement is a correct interpretation of these methods?

Both methods are experiments because sun exposure is assessed in both methods.
Both methods are observational studies because neither method attempts to influence responses.
Method A is an experiment because it compares many brands of sunscreen, while method B is an observational study.
Method B is an experiment because it randomly assigns volunteers a sunscreen, while method A is an observational study.

Answers

Answer 1

Answer: Method B is an experiment because it randomly assigns volunteers a sunscreen, while method A is an observational study.

Step-by-step explanation:

Based on the information given, we can infer that method A is an observational study. An observational study simply refers to the study whereby the researchers just observe the impact of a rise factor without them trying to change the people or things exposed to it. This can be seen as the survey adults visited the beach on the busy weekend asking each adult the brand of sunscreen that they use and then assess their arms for sun exposure.

Method B is an experiment. An experiment refers to a test that's carried out in order to evaluate a particular hypothesis or theory. Method B is an experiment because it randomly assigns volunteers a sunscreen.

Therefore, the correct option is D.


Related Questions

Determine the value of a.

Answers

It should be 10.6 inches.. can I get brainliest ?
It would be about 10.6 inches. Is this correct or no?

1) 3n² + 5n +7
A) quadratic monomial
B) cubic binomial
C) constant trinomial
D) quadratic trinomial

Answers

Answer:

D

Step-by-step explanation:

it is a quadratic trinomial

there are 240 students who attend Elmwood school. Two thirds of the students have brown hair. how many students have brown hair? how many students do not have brown hair?

Answers

Answer:

160 has brown hair while

80 do not have brown hair

Step-by-step explanation:

two third means 2/3

therefore to find how many student have brown hair,

we say- 2/3 x 240 = 160

since we know that 160 students have brown hair, we just subtract it from 240

i.e 240 - 160 = 80

Please help!!!!!!!!!!!!!!!!!!!

Answers

Answer:

there are infinitely many solutions

Step-by-step explanation:

1/2(b + 14) is the same as (b + 14) / 2

6x+2 = 5x+18 PLS QUICKKKK

Answers

Answer:

16

Step-by-step explanation:

Equation : 6x+2=5x+18

Like Terms : x + 2 = 18

Like Terms Again : x = 16

Answer:

6x+2=5x+18

6x-5x=18-2

X=16

Step-by-step explanation:

First you need to group numbers of like terms in one side. Then when you take the other number to the other side of equal sign changes it's form eg +6 change to - 6

Help with the calculus problem please

Answers

The area of the region is equal to the area under the curve y = cos(x) over the interval 0 ≤ x ≤ π/6, given by the integral

[tex]\displaystyle\int_0^{\frac\pi6}\cos(x)\,\mathrm dx = \sin(x)\bigg|_0^{\frac\pi6}=\sin\left(\frac\pi6\right)-\sin(0)=\boxed{\frac12}[/tex]

which follows from

• the fact that d/dx [sin(x)] = cos(x)

• the fundamental theorem of calculus

What is the answer please help no links no links

Answers

70 %
30/45 = 2/3 = about 0.67 and 70% (0.70) is the closest

A rectangular picture is twice as long as it is wide. If the
area of the picture is 288 in^2, what are its dimensions?

The dimensions of the picture are_____ in long by_____ in wide.

Answers

Answer:

24 in long by 12 in wide.

Step-by-step explanation:

l=2w

288=(2w)×w

288=2w^2

144=w^2

12=w

width is 12 inches. Plug that in to find length...

l=2×12

l=24

chicken wing chicken wing

Answers

Answer:

hot dog and baloney :>

Step-by-step explanation:

yeet

Answer:

Hot dog and baloney

Chicken and macaroni

Chilling with my homies

I heard it so many times :)


Need help with this problem

Answers

I’m pretty sure it is linear sorry if it’s wrong have a good day

Repeated-measures and matched-subjects experiments
Repeated measures experiments measure the same set of research participants two or more times, while matched-subjects experiments study participants who are matched on one or more characteristics. Which of the following are true for both a repeated-measures experiment and a matched-subjects experiment when used to compare two treatment conditions?
A. If the researcher has n number of participants to use in the experiment, then the degrees of freedom will be the same in a repeated-measures experiment or in a matched-subjects experiment.
B. The researcher must compute a pooled variance to compute a t statistic.
C. The researcher must compute an estimated standard error for the mean difference score to compute a t statistic.
D. Participants in both types of experiments are all measured the same number of times.
A matched-subjects experiment produced at statistic with a df of 13. How many subjects participated in this study?
a. 13.
b. 28.
c. 26.
d. 14.
For a repeated-measures experiment comparing two treatment conditions, the t statistic has a df of 17. How many subjects participated in this study?
a. 18.
b. 17.
c. 36.
d. 34.

Answers

i guess 26 first question ...

What is the length of de

Answers

Answer:

B. 37 units

Step-by-step explanation:

DE = 4x + 1

AB = 11x - 25

DE is a midsegment of the ∆ABC

Therefore:

DE = ½(AB) => Triangle Midsegment Theorem

4x + 1 = ½(11x - 25)

2(4x + 1) = 11x - 25

8x + 2 = 11x - 25

Collect like terms

8x - 11x = -2 - 25

-3x = -27

-3x/-3 = -27/-3

x = 9

✔️DE = 4x + 1

Plug in the value of x

DE = 4(9) + 1 = 36 + 1

DE = 37

What is the measure of ZB, in degrees?

Answers

Angle B is 32 degrees

This triangle is an isosceles triangle so two sides are equal, angle A and angle C are equal so 74+74=148 and then a triangle equals 180 degrees so you subtract the angles of A and C to find B. 180-148=32

I’ll give you brain list if you solve it

Answers

Answer:

1000$ is the correct ans I think ?

26,720 inches are equal to _______ miles.

Answers

Answer:  0.42171717 miles

Step-by-step explanation:

 for  inches to mile conversion  divide  by 63350

so got 0.421717

What is the volume of the figure below, which is composed of two cubes with side lengths of 6 units?
A.
216 cubic units
B.
360 cubic units
C.
432 cubic units
D.
36 cubic units

Answers

you didn’t figure it out

Fill in the number to find the sum . 2/10 + /100= 50/100 a. 30 b. 10 c. 28 d. 52

Answers

Answer:

2/10 + 30/100 = 50/100

Step-by-step explanation:

First, you want to multiply 2/10 by 10, to get the same common denominator in both numbers, you would get 20/100. Then, its pretty simple from there, you just add the number that gets you to 50, which is 30, 20 + 30 =50. I Hope This Helps :)

The required missing number is 30. So, the correct answer is (a) 30.

What is arithmetic?

Arithmetic is a branch of mathematics that deals with the study of numbers, their properties, and their operations. It involves the basic operations of addition, subtraction, multiplication, and division.

Here,
To find the missing number, we can use the fact that 50/100 is equivalent to 1/2.

So, we need to find a number that, when added to 2/10, gives 1/2 as the sum.

We can write this as an equation:

2/10 + x/100 = 1/2

Multiplying both sides by 100 to eliminate the denominator, we get:

20 + x = 50

Subtracting 20 from both sides, we get:

x = 30

Therefore, the missing number is 30. So, the correct answer is (a) 30.

Learn more about arithmetic here:

https://brainly.com/question/11424589

#SPJ2

You have recently signed up for a new job and noticed this policy for retirement savings. Invest $200 and the employer does 70% matching for 35 years at an interest rate of 4.8%.

Find the total amount that the employer contributes each month.

What amount will you have after 35 years?

How much money have you deposited into the account yourself?

How much more money is in the account than what you have deposited?

Answers

Answer:

Amount per month contributed by employer $ = 200*0.70 = 140

Total amount employer contributes $ = 140*420 = 58800

Total amount employee contributes $ = 200*420 = 84000

Total amount after 35 years with interest calculated AT 4.8% (Employer + employee + interest) $ = 371024.67

Interest amount for 35 years accumulated $ = 228224.67

Amount deposited by employee $ = 84000

Excess amount in the account over the employee contribution

Including employer contribution $ = 287024.67

Excluding employer contribution $ = 228224.67

Step-by-step explanation:

LOOK AT THE PICTURE FOR STEPS

If sin(38°) and cos(52°) does that add up to 90°?

Answers

Answer:

38 plus 52 is in fact 90, but Sin and Cos will be different.

Step-by-step explanation:

Honestly I haven't learned Sin or Cos

no they don’t add up to 90 it will give you 1.23

but actually 38+52=90 but putting sin and cos will definitely differ

?????????????????????????????????????????????????

Answers

it's not possible

I think -7 is the right answer but it's not possible actually

Answer:

c. -7

Step-by-step explanation:

(x+57) + (63+67) = 180

(x+57) + 130 = 180

x + 187 = 180

x = 180-187

x = -7

why did I make it equal to 180?

all the angles in a triangle always equal 180 :)

Can someone help me with this please

Answers

I’ve attached my work...
Hope it helps!
Math-way app for problems like number 2
Have a nice day:)

find the volume of the sphere radius is 20 meters

Answers

Using the formula 4/3*pi*r^3=V
V= 1675.52

Hope works for u :)
4000/3(pi) or
4188.79 [corr to 2 decimal place]

the formula to the volume of sphere is [V= 4/3(pi)(radius)^3]. if the diameter of the sphere (which is as shown as in the picture provided) is 20 meters, the radius is 10 meters.


I WILL GIVE BRAINILYEST!!!This is a graded discussion:
Modules
Mathematical Modeling Discussion
Syllabus
Grades
99 Co
5.272 a
People
0.31 MeV B 99.80%
Office 365
1.48 Mev B-
1.1732 MeV Y
0365 Email
1.3325 MeV Y
The rate of decay of a radioactive substance depends upon the
amount present initially. The mass y (mg) of the radioactive substance
cobalt-60 present in a sample at time < (years) is represented by the
-0.13151
exponential equation y = 50 e
Answer the following questions in complete sentences.
1. How does the exponential equation above compare to the equation
for simple interest that is compounded continuously? Explain the
similarities. What is the initial amount of cobalt-60 in the sample?
2. How much cobalt-60 is left after 8.4 years? Show your work
3. What would be the y-intercept of the graph? What does it
represent?
4. After how many years will the amount of cobalt-60 left be 6.25
mg? Explain what happens to the cobalt-60 after 50 years?
5. Discuss some real-world" examples and uses of cobalt-60

Answers

Answer:1.40

2.20

3.100

4.39

5.7

7

Step-by-step explanation:


A cone has a diameter of 20cm and a height of 12cm, what is the volume of the cone?

Answers

Answer:

The cone volume that has a diameter of 20cm and a height of 12cm is 5,026.548246 cm^3 or 5,027 cm^3

Make sure to round your answer to the nearest significant figure that you're asked.

Step-by-step explanation:

The formula for the volume of a cone is (height x π x (diameter / 2)^2)/3, where (diameter / 2) is the radius of the base (d - 2 x r), so another way to write it is (height x π x radius^2) / 3

Which is the sum of 14t/10t^2 + 5t^2+40t/10t^2

Answers

Answer:

7t/5^3 + 5t^2 + 4t^3

Step-by-step explanation:

You deposit $4,400 into a bank account with an annual simple interest rate of 2.1%. a. How much interest does the account earn in 15 months? b. What is the balance of the account after 15 months?

Answers

Hi I don't know how to explain this in steps but the interest is 15523,2

The balance is 1108,8

An aquarium 4 m long, 1 m wide, and 1 m deep is full of water. Find the work needed to pump half of the water out of the aquarium. (Use 9.8 m/s2 for g and the fact that the density of water is 1000 kg/m3). Show how to approximate the required work by a Riemann sum.
Express the work as an integral.
Evaluate the integral.

Answers

Answer:

Workdone = 4900joules

Step-by-step explanation:

Work-done = force x distance

Force = mass x acceleration

If we suppose that the aquarium is at height 0 at the top and height 1 at the bottom (since it's 1m deep), then we need to lift the slide at height x by x metres.

Mass = Density x Volume, therefore force needed to lift the slice is given is

F = density*volume*∆x*acceleration

Since we the mass changes as we take out water then there will be a change in height, for this reason we have ∆x.

Acceleration is due to gravity, therefore g=9.8m/s²

Density = 1000kg/m³

Volume = 4*1*1 = 4m³

F = 1000*4*∆x*9.8 = 39200∆x

Since our distance from the top of the aquarium to the bottom is x metres, then

Work-done = 39200x∆x

To find the total workdone, we find the integral of 39200xdx and the limit will be from 0 to 0.5 since we are to pump halfway of the aquarium. Integrating that we have

19600*x² limit from 0 to 0.5

19600(0.5² – 0²) = 19600(0.25 – 0) = 19600(0.25) = 4900joules

what is 5 cm in mm. NEED HELP ASAP !!!!!!!

Answers

50 millimeters is your answer

Which of these is a safe practice when working with horses?
A . use a firm, loud voice
B . stay in the horse’s blind spot use quick-release knots for easy escape
C . if unattended, leave the horse tied up

Answers

Answer:

i think the awnser is c . if unattended, leave the horse tire up

I have a question for special product patterns.

It is in the attached image.

Answers

its answer 3 because they are the only difference with two squared numbers
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